Create a calculator

Getting started

Building support

Theoretically, a Calculator-style model could be built for any country, region or city by anyone with the necessary time, money and modelling skills. Once completed, there is probably an audience that would find such a tool useful, or at least interesting. A Calculator is really powerful, however, if it is built with support from government from the outset. This focuses the project on the questions that those with influence really want answers to, and also creates a ready-made audience keen to take on board the key messages.

Finding the relevant organisations to engage can be a challenge as every country and region has its own system. In the UK, responsibility for energy and climate change resides in one single department in government, making it a natural home for such a project. In other countries, the situation might not be as clear. Ask yourself which organisation has responsibility for energy or environmental policies. Perhaps there is one department that has responsibility for long-term planning in general.

Getting a government body to take ownership of the project is extremely important, but remember that you will still need to consult other organisations across government since the Calculator covers everything from building regulations to public transport policy. Involve stakeholders as early as possible so that they feel part of the project. If you only start consulting them once the Calculator is built, it is likely that they will not be engaged and that you will miss out on the opportunity to learn from their expertise. Using their knowledge to build the Calculator is much easier than finding out you’ve made a mistake once it is completed when it is much harder to fix.

It is likely that a lot of knowledge about the energy system and modelling expertise is held not just in government, but in universities and NGOs. Talking to researchers from all backgrounds can be very helpful. It may be more effective for a government to commission a university or other organisation to do the modelling work for them, for example, the University of Cape Town built the South Africa Calculator in partnership with their Department of Environmental Affairs.

Building a team 

In our experience, a Calculator can be built by a core team of between 4-7 people. They do not necessarily all have to work full-time over the course of the project – many teams have developed a Calculator while continuing to work on other things. 

The team is usually made up of: 

  • A project leader – focused on political and stakeholder leadership 
  • An Excel expert – to bring all the sectors together into a working tool 
  • A number of sector leads – to find evidence on one area and engage with expert stakeholders 

The project leader will take on the project management role, and will lead on engagement, both within government and with outside stakeholders. They must be able to convince others to get involved and support the work, and must make sure that the Calculator is aligned with other government priorities to make it as successful as possible. Organisation and communication skills are important, and experience of working within government is useful to help understand who needs to be consulted and when. 

When choosing an Excel expert, it is perhaps most important to find someone who is logical and skilled at using Excel, rather than an expert in energy – although if they don’t have a good understanding of how the energy system works before they start, they will have to learn quickly. Attention to detail is obviously a necessity, as small errors in the detail of the model can become magnified in the final results. 

Sector leads should have good research skills and be able to quickly develop an understanding of a particular sector (e.g. transport or electricity generation). They should be able to synthesise expert views and present their results clearly. The number of sector leads you will need will depend on how you are dividing the energy system and the particular aims of your model. 

Developing a project plan 

The teams who have successfully built Calculators have found that it takes around nine months to build a working first version; three months to secure support and put together a team, and then six months working on the model itself. 

The emphasis should be on launching the Calculator as early as possible. One of the great strengths of the Calculator approach is that it is open, allowing others to view the whole model and suggest improvements. Releasing it early as a “work in progress” rather than as a finished product means that errors can be found and corrected before any policy is based on its results. Most teams choose to release the first version with a ‘call for evidence’ or a consultation, allowing them to collect feedback directly from experts in a collaborative (rather than adversarial) way. The feedback can then help to improve the model and a new version can be released. 

When drawing up a project plan, it is important to consider other events that may impact the timeline. Perhaps there is an existing conference that would be perfect to launch the Calculator, or perhaps there is a busy period coming up that is best avoided. 

Mapping your emissions

The 2050 Calculator works by dividing the energy and emissions system of a country or region into different sectors and modelling the energy demand, supply and emissions in each sector across a 40-year period. It then adds it all up to show the total figures. 

The first step is to decide how to divide the energy and emissions system. This will depend on the particular economy you are looking at and what you are wanting to find out. Residential heating, for example, is a major source of energy demand in the UK due to its mild climate. In a country like Thailand, air conditioning is a more important area to focus on, so cooling is a more appropriate choice. If a sector is not relevant to you (for example, wave power in a land-locked country), do not include it. 

For the UK Calculator, industry was modelled as one sector, but the Calculator of the Belgian region of Wallonia divided industry into a variety of sectors so it could be more accurately modelled. The Indian Calculator divides electricity supply into low-carbon technologies and conventional technologies because the team decided it was a useful distinction for reporting results. The Chinese Calculator divides rural and urban transport.

In general, you should aim to have as few sectors as possible, to allow quick use of the tool. You should cover the whole economy and all emissions (it’s best not to ignore land use or industrial process emissions) and include all expected sectors, even if they are small (for example, if your audience thinks that rooftop wind turbines are an important potential energy source, then it should be included even if this is factually incorrect). 

As a rule of thumb, 40 sectors is about right. We recommend starting from top-down, rather than from bottom-up (i.e., don't start by thinking of all the possible types of vehicles and how they might be modelled; rather start by thinking about the transport sector and the fewest sub-divisions that are possible). 

For reference, here is a list of the sectors that are universal to most Calculators: 

  • Buildings (often separated into domestic and commercial and include the efficiency of lighting and appliances)
  • Transport (often split into passenger and freight) 
  • Industry (sometimes with separate levers for different major industries) 
  • Electricity production 
  • Bioenergy 
  • Agriculture and land use 
  • Waste and recycling 

Mutually exclusive, collectively exhaustive (MECE) 

The different sectors in the energy economy overlap and interact with each other to produce overall supply, demand and emission figures. It is crucial to understand this interplay and to take it into consideration when designing the model, but not to get overwhelmed by it. Everything should be covered once, but only once. The MECE principle (mutually exclusive and collectively exhaustive) should become a mantra for the project, so that the same energy or emissions inputs do not appear multiple times in the model, making results inaccurate. For figures that are relevant to multiple sectors, exactly where they go in the model will be a matter of personal preference. In such cases, as long as everything is properly documented, there is no right or wrong answer. 

It may be helpful to consider linked technologies together, as this will minimise interaction between sectors; for example, you could include one sector for heating and insulation as they often interact.

Keeping it simple 

The abiding principle when building a Calculator is the model should be “as simple as possible, but no simpler” – you have to strike a balance between making sure it is easy to understand, yet still analytically robust. 

If you can simplify the way in which you model a sector without compromising accuracy too much, then do it. The overall figures, and the major driving forces in supply and demand behind them, are what you need to get right. Modelling the intricacies of each sector can make it more difficult for non-experts to understand what is going on. Understandably, experts may not like this approach initially, but it has been key to the Calculator’s success.

Building driver trees 

Once you have divided the energy system into sectors, it is time to look at each sector in more detail and identify the major drivers behind them. This will help you to identify which levers you can pull to change demand and supply. You do this by drawing ‘driver trees’. These are simple diagrams that show the way in which supply and demand for energy relate to produce outputs. At the top of a driver tree, there should be the output the Calculator is focusing on, such as emissions or fuel use. 

Driver trees are another way of displaying the data and calculations you will need in the model. If you get them right, building your model will be a lot easier.  

Choosing your levers 

Once you have a driver tree for each sector, you can quickly see how changes in supply or demand will affect your outputs. Now you must choose which factors you think are the major drivers of change in the sector, and therefore which levers you would like to have in the model. Each lever will allow users to make a choice about what happens in the future. 

You can have any number of levers, but somewhere between 25-40 is particularly effective. The exact number will depend on your target group and how much time you want them to spend (or how much time they are willing to spend) using the tool. It is unlikely that a decision maker will be able to spend more than 30 minutes on the model. Generally, the more levers you have, the higher the credibility of the model, but the fewer people will be able to engage with it. 

To choose your levers, you must ask yourself: 

  • What has changed in the past? 
  • What is likely to change over time if we do nothing? 
  • What changes would have the biggest impact? 
  • What affect could policy or innovation have? 
  • Could we change people’s behaviour? 

Generally, each sector should have between 1-3 levers. If there are a few sectors that you really want to focus on, then you could have more. Remember you audience – if you choose an obscure variable to change, will a policy maker or an interested member of the public be knowledgeable enough to understand what they are changing and what the different options are? Choosing variables that are relevant to people’s lives is much more effective. 

As an example, if you are looking at international aviation, you could consider the following questions: 

  • Will people fly more in the future? 
  • Will more people fly? 
  • Will planes become more efficient? 

When choosing levers, it might be better to use “number of flights per year” rather than “average distance flown per flight”, as people know how often they fly but are rarely aware of how far they fly. 

Sometimes it is best to combine related technologies or behaviours together into one lever to make the model easier to use. You could, for example, use one lever for the deployment of all small-scale micro-generation, rather than separate levers for micro-wind, solar and/or hydro. Or you could combine demand for lighting and appliances into one lever because they are usually covered by similar policies. 

Choosing your outputs 

The Calculator shows many different impacts of the energy choices that are available. What outputs you choose to include or exclude will depend on what is most important to you. All the Calculators built so far have looked at greenhouse gas emissions, and some have considered costs, energy security (imports and exports, energy mix, energy balancing) and air quality. Water and biodiversity are also options which are being considered. 

Finding data 

Once you have driver trees for all sectors, it should be clear what data you will require to populate your model. When building an open model like the Calculator, the data you use must be either publicly available already, or you must have permission to make it publicly available. If you use anything confidential, you will not be able to publish the model. You must always keep this in mind when deciding what figures to use. 

Data sources will vary from country to country and region to region. Government statistical departments are a great place to start, but it could be that universities or other research organisations also have useful data. The government may already have some models containing data, which you could use. Where official data is not routinely collected or easily available, international bodies like the International Energy Agency (IEA) may be able to help. 

Not all the data you will need is country-specific. The laws of physics are universal, so you will be able to use many of the same assumptions and figures as used in previously completed Calculators; for example, the efficiencies of solar PV panels will be similar around the world, so assumptions can be used from an existing Calculator. Solar irradiance levels, however, will vary depending on your geographical location. 

Sometimes it can be difficult to get the data you need – perhaps you have divided sectors up differently from the data sources, so you cannot get the data to match; or the information just isn’t available in your country. In such cases, it is important not to compromise the logic of the model to fit the data. Instead, bend the data to suit the model. Use proxies, estimates and international precedents. Make sure you document the assumptions so users can see what you are doing and assess its suitability. 

Setting levels 1-4

Each lever in the Calculator will have four different options available to users, called level 1, level 2, level 3 and level 4. The levers represent trajectories for increasing levels of ‘effort’ over the period from now until 2050. What this effort means will depend on the aims of the individual Calculator; for example, in the UK Calculator, effort was always directed towards reducing greenhouse gas emissions. For demand levers, high effort means that energy demand was reduced; for supply levers, high effort means increasing the supply of low-carbon energy. In the Indian Calculator, effort on the supply side was targeted at increasing energy security rather than reducing emissions per se as the Calculator was focused on energy independence. 

Whatever the aim of the calculator, levels 1-4 are defined in the following way: 

  • Level 1: no effort 
  • Level 2: effort described by most stakeholders as achievable 
  • Level 3: effort needing significant change – hard but deliverable 
  • Level 4: the maximum possible due to physical/engineering/behavioural constraints only 

Defining each of your levers is a challenge, but one that is made a lot easier if you consult experts from government, academia, industry and NGOs. By crowdsourcing opinion in this way, your conclusions will be a lot more robust and confidence in your Calculator will grow. 

The forces at work 

Generally, there are three types of forces constraining how much effort is possible in a sector of the Calculator: 

  • Geographic constraint – for example, the number of houses that could have solar panels installed on them, the amount of land available to grow biocrops or the number of rivers that could be used for hydroelectricity. 
  • Behavioural constraint – for example, how much people would be willing to reduce the amount they travel, change their mode of transport or use air conditioning less. 
  • Engineering constraint – for example, the number of nuclear power stations that could be completed if we built at the highest rate ever seen in the past from now until 2050. 

While some levers will be affected by more than one of these constraints, usually there is one overriding constraint that can be used to guide your thinking when setting each level. 

More about level 1 

At first glance, level 1 seems the easiest of the four to pin down; however, in reality, it can be quite complicated. The idea of “no effort” is not the same as “business as usual” for many sectors. If we do nothing, that doesn’t mean that things will stay the same for 30 or 40 years. Depending on the lever, the following definitions of level 1 could be helpful: 

  • Tomorrow, the government announces that X technology is no longer supported, and it is clear that the private sector won’t support it alone. In this case, the technology would be phased out quickly, or not deployed in the first place if it is a new technology. 
  • No action is taken to change X behaviour, so current trends continue into the future. 
  • Public opinion was so strongly against X technology that the government prohibited its use. All existing examples of the technology will be allowed to run until the end of their useful life or aggressively phased out. 
  • Government goals are not being achieved in sector X. 

It is tempting to make level 1 a “business as usual” scenario that reflects current policy; however, defining it as “no effort” instead allows you to show what would happen without your policies, therefore showing where they add value. It also acts as a baseline that gives people more choice, enabling those with strong views to reflect their opinions (for example, people who are against nuclear power). 

More about level 4 

Defining level 4 for each sector is an exercise in extreme optimism. Level 4 is not what is likely or easily achievable, or perhaps even desirable for many people. It is the maximum that could be achieved for technical or practical reasons. Depending on the lever, the following definitions of level 4 could be helpful: 

  • Imagine an effort from government similar to the US Apollo programme for the behaviour or technology in question. What could be achieved? 
  • The opinion of your most ambitious credible expert (perhaps an “evangelist” for a particular technology), backed up by some evidence either from their own calculations or published work. 
  • Drawing an example of something achieved in another country. If they did it, why can’t we? For example, how much nuclear capacity could you build if you used the same high build rate seen in France during the 1970s and 1980s? 

Level 4 should be difficult to achieve, and this should be made clear to the user. The advantage of including difficult options is that the model is able to span the full range of opinion, so it can be supported by a bigger number of organisations. If you do not include the full range of options, the Calculator will no longer be a tool exploring the question “what if?” 

Levels 2 and 3 

Levels 2 and 3 will obviously fall somewhere between levels 1-4 in terms of effort, and are designed to show different levels of realistic government intervention for a technology or behaviour: 

  • Level 2 could be used to show your existing policies for a sector (i.e. you are already taking action and this is the impact it will have). 
  • Level 3 is more than what is currently being done. It should be ambitious, but the majority of experts should view it as achievable. 

Engaging stakeholders 

Once you have formulated draft levels 1-4, it is time to ask the experts what they think. We suggest holding a half-day or full-day workshop for each sector to gather experts together and get the debate going. 

Who should you invite? You want to get a range of opinion from the more conservative to the extreme end – there will be people who believe passionately in a particular technology or the potential for behaviour change. These voices should be welcomed as long as they have good evidence to back up their claims. The sort of people you may want to invite include: 

  • Representatives of major companies 
  • Representatives of professional or trade bodies 
  • Academics 
  • Representatives of environmental NGOs or action groups 
  • Representatives of women's groups, community groups and other marginalised groups 
  • Those working in government 

The focus should be on setting the levels, and perhaps some of the assumptions you have used. You should avoid discussing the underlying methodology of the model. This should already have been informed by stakeholders at an earlier stage. Opening up the debate again will be time consuming. At the start of the workshop, you should introduce the Calculator project and its aims. The main messages you want to get across are: 

  • The 2050 Calculator is designed to simulate different possible futures. 
  • It needs to take into consideration a wide range of possible scenarios to do this. Levels 1, 2, 3 and 4 enable this. 
  • We want your evidence to inform the levels. 
  • You don’t have to all agree – a range of views is good. 

There are many different ways you could get the discussion going. For example: 

  • You could show the draft trajectories for each lever in turn. Do the participants agree with level 1? Is level 4 too ambitious or does it not go far enough? Do they have any extra evidence you haven’t considered? 
  • Specify what assumption you are exploring, and then ask the participants to write down their viewpoint of what the number should be for each of the four levels on separate post-it notes. Gather all the post-its together grouped by level, and discuss areas of agreement and disagreement. 
  • Use an example from one of the existing countries. 

If you do not want to host large workshops, you could hold a series of smaller or one-to-one meetings with experts instead. The Calculator team in Mexico have used this approach. It takes longer, but you may get more honest or focused feedback. 

Writing your one-pagers 

Every lever in the Calculator has something called a “one-pager” that the user can refer to. It explains the background to the lever and what each level means. It is usually in PDF format and is embedded into the Calculator’s web tool or can be downloaded as a pack for use with the full Excel model. When writing one-pagers, it is extremely important to be clear and concise – remember that your audience may not be experts in energy, and so technical terms should always be explained.

A great one-pager: 

  • Briefly summarises the sector and the situation today. 
  • Briefly sets out the meaning of levels 1-4, and the key implications of each level of deployment. It should include all the main figures involved (being consistent with units so that they can be compared), but not so much detail that the reader will become bored or confused. 
  • Briefly discusses factors that the user should consider when making choices, for example, the effect on other levers, amount of land used or impact on air quality. Any likely social impacts, particularly those that differentially impact different sectors of the population, should be included. 
  • Illustrates the levels, ideally by comparing the deployment to historical levels or deployment in other countries to give an indication of how difficult or easy it would be to achieve. It could be helpful to include some information about how the levels were set. 
  • Illustrates the levels with a bar chart showing the amount of energy that sector produces or uses. This bar chart should have the same scale across every one-page note, so that the notes can be compared. Graphs, images and diagrams could be included as well. It’s a good idea to test one-notes on colleagues who are not working on the project to make sure they are easy to understand. 

Best of luck with your Calculator! If you have further queries, check out the Calculator Yammer group, where you can interact and ask questions and advice from members of the global Calculator community. Or email

Putting the Calculator online

One of the unusual things about the 2050 Calculator is that you can use it over the internet. This section describes why we did this, and what is needed for you to do it. 

Why build a web interface? 

  1. More people will use the model. 
  2. The model can be used in interactive presentations and debates. 
  3. The model will run faster. 
  4. It will be easier to share results. 

What sort of web interface should you build? 

Choices around: 

  1. Number of choices you present 
  2. Range of consequences you present 
  3. Balance between presenting numbers, and presenting impressions 

What do you need to build one? 

Skills required: 

  1. Some Javascript 
  2. Some ability with 'the command line' 
  3. Ideally, some ruby, but not essential 

Level required: 

  1. Someone who is enthusiastic about programming and has experience (perhaps as part of an engineering or science degree) is sufficient. 

Time required: 

  1. If it is similar to the UK version, then it can be ready in a couple of weeks of amateur time. 
  2. If it is different from the UK version, then it may take some months. 

What steps should you take? 

  1. Decide what consequences are important to your users 
  2. Decide what choices are important to your users 
  3. Get the UK version working on your system 
  4. Replace the UK model with your model 
  5. Adapt the first screen of the online tool to fit your needs 
  6. Gradually introduce other charts and views 

When should you start? 

Start as soon as you have a more-or-less complete spreadsheet. The spreadsheet doesn't need to be finished – it is okay for the numbers and formulae to change. It is best, however, if the structure of the spreadsheet (e.g., number of years, number of sectors, output tables wired up) is more-or-less finalised. 

Things you might be tempted to do (but perhaps shouldn't) 

You may be tempted to: 

  1. Try and drive the Excel spreadsheet directly, using Microsoft interfaces. We've found that this is too slow and too unreliable for a good user experience. 
  2. Put more than 40 levers on the online interface. We found that this means you can't get a good overview of what’s going on, and takes too long for people to use. 

Reducing the number of choices you present to the user 

You will probably want to have a version of the web interface for experts that pretty much replicates the Excel file, but in a quicker, easier to use format. You may also want to have a simpler web interface for non-experts (in the UK we call this My2050). To make it simpler, you may need to reduce the number of choices you present to the user. 

This involves going through each choice in the Excel spreadsheet and deciding whether to: 

A. Keep the choice in the simple interface (e.g., Nuclear power was kept in the UK My2050 version)
B. Not include the choice, but instead leave it set at one level (e.g., Geosequestration is always set at level 1 in the UK My2050 version)
C. Combine the choice with another choice (e.g., The heating choice lever in the UK My2050 version actually controls four levers in the Excel spreadsheet at the same time). 


  1. The source code to the UK interface is available at

Launching your Calculator

Congratulations on producing a working Calculator and web tool! It is now time to let the world see it, improve it and use it. The first step is to release your Calculator as a prototype version with a ‘call for evidence’ so that experts and stakeholders can provide feedback. We recommend that you do this as soon as possible – to allow changes to be made more easily. 

The benefits of being open and transparent 

It is worth reiterating that by publishing your full model, you increase the chance of its success. Here are a few reasons why: 

  1. There may be ideas you haven’t thought of yet. By letting your target audience provide feedback before the Calculator is complete, the tool can be improved, making it more likely to be used in future. 
  2. No matter how careful its creators are, every model will have bugs. You are more likely to find them if you open up the model and allow others to look inside. You shouldn’t be scared of this – it is better to find bugs and correct them rather than to leave them. The risk of finding a mistake is much lower if you find it and correct it now before any policies are based on the model’s results. 
  3. People will trust the results of the model more if they understand how it works and know what data it is based on. This is true for policy professionals, politicians, journalists and members of the public. 

Example pathways and key messages 

You may want to consider publishing some example pathways at the same time as the model. Although one of the benefits of the Calculator is that there are no ‘right’ answers, supplying your users with options is a good way to get them thinking about the model’s implications; for example, you could have ‘maximum supply effort, no demand effort’ and the converse ‘no supply effort, maximum demand effort’ pathways, as well as pathways that meet your national targets. You do not have to label them as officially approved pathways if it would be politically difficult, and can instead stress that they are examples only. You could even get your key stakeholder groups to design their favourite pathways for the future. By doing this, you give your stakeholders a concrete way to engage with the Calculator project, proving that the tool is useful for a variety of audiences. 

It is extremely powerful to publish the key messages you have learned from the Calculator. As the team that developed the model, you will have spent a lot of time exploring the impact of various levers and combinations of levers, as well as the possible overall trajectories for supply, demand and emissions. The messages are particularly useful for policy makers who have limited time to use the Calculator, as they can benefit from your experience when developing policy. You could answer questions such as: 

  • How much fossil fuels could cost the country in 2050? 
  • How much demand for electricity could there be in 2050? 
  • Could you decarbonise the electricity grid? 
  • How much could you achieve with energy efficiency alone? 
  • What are the limitations of bioenergy? 

Holding a successful launch 

The tactics you use for launching your Calculator’s ‘call for evidence’ will vary depending on your country or region’s own circumstances. You may want to have a soft launch, publishing the model with little fanfare and inviting particular experts or organisations to comment. If so, you could hold a public launch for the second, improved version of the Calculator instead. Or you may want to launch your initial version publicly to gather feedback from as many people as possible in the shortest time frame. Think about what is most appropriate for you. 

If you want a public launch, you could hold a press conference or a more informal launch event that the press is invited to. The presence of senior officials (like ministers) sends a message that this is an important tool and that it has the support of the government. If you decide to hold a press conference, it is important to think about the implications of the model that you would like covered. Journalists are more likely to be interested in what you have found out through using the tool than the fact that the tool exists. 

It is important to make it easy for people to provide feedback. You could, for example, have a link on the web tool to your ‘call for evidence’ page and provide an email address on the page for visitors to respond.  

Improving and re-launching the Calculator 

When you receive responses to your ‘call for evidence’, it is, of course, imperative that you read the comments and make changes as appropriate. Others may have found mistakes or will think of new ideas to improve the Calculator and make it more relevant to your target audience. Set aside time for this process. You may want to use this opportunity to expand the Calculator significantly, perhaps by adding new sectors like land use or air quality, which will require further engagement with experts and stakeholders. 

You can then re-launch the new, improved version of the Calculator. It is up to you to decide how big your re-launch should be. If your first launch was low-key, then you may want to make this your main launch with as much press coverage as possible. If changes are relatively minor, you may wish to quietly update the available online version. 

Influencing policy

The finished Calculator should be interesting for everyone working on energy and climate change issues; however, to make it something more than just a fun tool, it needs to be used by those with power and influence. It should be used to bring real scientific evidence into the debate around energy issues, and in turn to inform decision making. 

When discussing strategy and policy, the Calculator tool can be used to create a common language to test out different scenarios. By laying out all the options that are technically possible, it lets you easily compare different combinations and see their implications. 

Testing existing policies using the calculator 

As a start, it is good to use the Calculator to evaluate the policies you currently have in place. Do your policies align with the key messages from the Calculator? Are your policies aimed at the right sectors, and are they ambitious enough? Or are you promoting technologies or interventions that will have little impact, or even a negative impact, in the future? A short bit of analysis looking at these questions could be circulated to policy teams to create awareness. 

Alternatively, you could create a ‘current policies’ pathway using the Calculator. To do this, you will need to convert government aims or progress into choices on each of the levers. In practice, this can be quite difficult, as the aims of each policy may not have been expressed in the same terms used by the Calculator. Quantifiable predictions in terms of efficiency, supply or demand may not have been released, and adding up the impacts of different policies can be very complicated; however, even a rough pathway can be useful in internal discussions, helping you to identify gaps in your plan. 

Developing new plans and policies 

The Calculator can be used to inform the strategic direction of a country or region’s energy or climate change policy. The key messages from the Calculator should be your starting point. If your existing strategy does not match the Calculator messaging, then consider changing it. You want your policies to concentrate on the levers that make the most difference. 

Because of the huge uncertainty around many of the options available in the Calculator (for example, the deployment of carbon capture and storage technologies at scale), it may be best not to set a strict pathway for the country or region at this point. 2050 is still quite a long way away. Consider releasing a few possible pathways instead. 

You should consider a range of factors when developing your plans, as there are trade-offs that need to be balanced in a lot of areas. Potential co-benefits (for example around energy security, forests, air quality and gender equality) should be considered when choosing and implementing a pathway.

Data management and data reporting 

Many countries, particularly developing ones, have limited emissions and energy reporting capability. A Calculator provides an easy way to record the past and report progress. 

In most Calculators, the modelling begins at a single base year, which is as close to the present day as possible; however, there is no reason why historical information cannot be put into the model so that it stretches back in time with real data, and also looks to the future. Once complete, it should be updated regularly with each year’s statistics, so that it becomes a record of the country or region’s energy and emissions. As well as making reporting easier, this could actually improve the user experience with the traditional forward-looking aspects of the Calculator, as future scenarios can be easily compared to past trends. 

Engagement and education

Climate change and energy security are two of the greatest challenges we face around the world. Yet, there is still little understanding of the impacts they could have or possible solutions. Lack of awareness is not just a problem among the general public, but also for those in business, industry and even in government and politics. The Calculator can be used as an interactive educational tool to help get people thinking about these issues and to show that the government is thinking about them too. 

Web tool - Influencing the influential 

The web tool version of the Calculator is great for those who work in energy, industry, transport, housing and the environment. It includes all lever options in an easy to use format. It can help people understand the energy system, identify choices that make the biggest difference and let you know their preferences. We encourage you to promote the tool within your own organisation, other government agencies, universities and companies. There are many ways you can reach your audience: 

  • Face-to-face approaches – including one-to-one briefings, workshops in which people build a pathway together and/or presentations. There are a lot of existing events that your target audience attends, where you could present the Calculator and its key messages. 
  • Teach the teachers events – Help others to talk face-to-face about the Calculator by holding events and/or producing toolkits to help people demonstrate the Calculator. 
  • Thought leadership – Create awareness about the Calculator by including your key findings in wider documents, press releases and/or writing blogs for social media. 
  • Competitions – Hold a competition within your organisation to encourage people to submit pathways to you. The winner could either be randomly selected or could have produced the ‘best’ pathway in a particular way. 
  • New staff induction – Make the Calculator part of the induction programme for new staff in your organisation. 

My2050 – a tool for public engagement 

My2050 is a simplified version of the full Calculator with an attractive user interface. It is designed to get members of the public, including children, interested and engaged in energy and climate change issues. 

The model has far fewer levers to play with – for example, the UK’s My2050 has 14 levers, while the full web tool has 42. You have to think carefully about which levers to choose. As a group, they should cover all the major parts of the energy system and all the big choices we need to make (ignoring the levers that have a low impact). Individually, they must be engaging and easily understandable for someone with no background in energy and climate change. Sometimes you may have to combine a few of the full Calculator’s levers together to make sure that you cover all the choices that are available. 

This user group will likely be less interested in, for example, the exact fuel mix used in bioenergy power stations, so it is a good idea to choose levers that relate to people’s daily lives, like transport or home energy efficiency, as well as issues that really get conversations going, like whether to use nuclear power or renewables.

The user interface should be straightforward to use, but also engaging and fun. Graphics are important – think about the best way to display data and results. Graphs can be effective, but you may want to use animation to show the impact of the user’s choices, for example, you could show a landscape where solar farms or electric vehicles appear, or a house which the user makes it more efficient. You could even display the secondary results of the user’s pathway, like air quality or temperature changes. This is a chance to be really creative. 

The My2050 version can also be made into a game by having a target or goal that the user has to reach. In the UK, the goal was to reach the country’s emissions reduction target set in legislation. In some countries, the goal could be more difficult to define – you could always ask people to create a 2050 world that they would like to live in. 

Users should be able to submit their pathway to the modelling team to allow a better idea of what the public are thinking, and also so the user feels that their work is being heard. 

The UK My2050 website was developed by an external agency (Delib). All of the images and back-end codes are owned by BEIS and can be shared. Some countries have subsequently used a slightly different approach to producing their version of My2050 which may be more quickly and easily adopted. 

Using My2050 

Now that your My2050 is ready, it is time to get people using it. There are many tactics you could use to engage your audience, but here are a few ideas: 

  • Use the press to spread the word – getting a few stories into newspapers, magazines or on popular websites will increase your potential audience. Although there are people who are already interested in energy and climate change, your tool will have the most impact if you can get people to use it who don’t usually think about these issues.
  • Use social media – make sure that people can share their finished pathway on social media accounts, so that their friends can see it and have a go. 
  • Run a competition – you could offer a prize to one lucky user picked at random, or perhaps to the person who gives the best answer to the question “I chose my 2050 pathway because…” 
  • Hold workshops – you could arrange workshops for interested members of the public across your country or region, or perhaps hold small workshops at existing conferences. 
  • Have a stand at an exhibition – My2050 is quick and fun to use, so it works well as a drop-in activity. Consider having a stand at science, technology or education exhibitions so that people passing can have a go at using the tool. 

Encourage its use in schools – My2050 is a great way to explore issues around energy and climate change for children of secondary school age, and it is relevant to subjects like geography, science and maths, as well as the social sciences. Create a website or resource aimed at teachers to show them how they can use the tool in class and explain what the pupils can learn from their experience.

Keeping the Calculator alive

Your Calculator should be a living tool that is added to and updated to suit your needs. Perhaps there is a new question you want to answer, or opinion has changed about how ambitious your trajectories should be. Maybe more recent data has become available that could be used as a new baseline to make sure your results are as accurate as possible. Keep improving the tool to maximise its impacts.

The Calculator network 

With so many teams around the world building their own Calculators, there is a great opportunity to share experiences and expertise, and to help spread the Calculator message of transparent modelling and evidence-based policy making. That’s why we’ve created a website with resources and an online community – We hope you will use it to ask questions and get support, but also to support others. Every Calculator team has unique challenges, which bring their own skills and ideas. Your challenges may be useful for someone just starting out or facing similar issues. 

Beyond energy and climate change 

The Calculator approach was developed to answer questions about energy, but there is no reason why it couldn’t be used in other spheres of government, business or even everyday life. The Calculator does two things well which are easily transferable: 

  1. It models each sector using a ‘driver-tree’ approach, showing the major forces that produce overall figures. Such an approach could be useful in understanding anything with a quantitative description. 
  2. It brings all sectors together in a common framework. This could be useful in any subject that involves trade-offs.

Here are some ideas for ways the Calculator could be used: 

  • Land use – with a limited amount of land available in each country, there are likely to be trade-offs around how the land is used as populations grow and economies develop. A land Calculator could ask how much land you need for agriculture or housing, or how much food could be grown using different farming techniques. 
  • Taxation – a tax Calculator could help you understand how different combinations of tax policies affect overall tax revenue. 
  • Government spending – a government budget Calculator could help explore per capita spending in different sectors and compare this to outcomes. It could provide quick insights into how effective spending is, which areas should be prioritised and an estimate of future subsidies. 

You may have your own ideas – please let us know by contacting