Game to Cut CO₂ Emissions

Energymixer.uk offers a game where you can play to produce the cheapest clean power for the UK.

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Above you see an example of me “winning” the game summer 2020 Energy challenge. I pulled off producing zero CO₂ emissions for two weeks straight with varying weather pattern while keeping all the lights on.

The challenge in this game is to try to achieve this while keeping costs per MWh of electric power produced down to a minimum. In this case I managed to keep the cost at £78/MWh. For comparison, if I ran on only gas power the cost would have been £42/MWh with a 46GW capacity.

Nuclear power while having no CO₂ emissions more that gas. E.g. in this game building 14GW capacity of nuclear will cover 32% of electricity demand at a cost of £20/MWh.

12GW of gas power will cover 31% of electricity demand at a cost of £13/MWh. So in this game Nuclear power is about 50% more expensive than gas.

Renewable power in contrast is really cheap. If we spend as much as £20/MWh on wind power we get 43% of our electricity demand covered. If we use solar power we get 37% covered.

The problem with renewable energy of course it that it doesn’t produce power exactly when you need it. That is what this game allows you to experiment with to get right.

Let us look at some different scenarios. We have already looked at a combination involving nuclear power and renewables.

Using No-Nuclear Power

What if you don’t want to use Nuclear power? What are our options then? I could build 168 GW of wind power capacity and 2000 GWh of storage. That keeps the lights on and emits zero CO₂ both weeks, however it costs a staggering £131/MWh.

So that is impractical, but it turns out that we can reach the same cost per MWh as our nuclear solution by using gas power and storage. This solution has 46 GW capacity of gas power, which is enough to cover all electricity production in case the wind isn’t blowing at all.

For a good week, you can see that the gas power plants only get turned on 2 out of 7 days.

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So while this solution does not cut CO₂ emissions to zero it is a very promising solution as you can see that the gas plants are only turned on about 10% of the time.

But so much smaller amounts of fuel needed could more easily be supplied by biomass solutions. And the prices here are artificially inflated, as the fossil fuel plants are already bought and paid for. While in this game you have to pay for them. The real cost is just the fuel. Since the plants are paid for we can afford to pay more for fuel by e.g. buying biomass instead. Alternatively we could use synthetic fuel. Notice the excess of 16% power produced. This excess is in a sense free power which somebody could have used produce hydrogen from electrolysis which could be combined with CO₂ from biomass plants to produce methane or some other hydrocarbon synthetically.

This could power gas plants later.

Storage Prices are Unrealistically High

While the game obviously has to simplify things, it is worth keeping in mind that the way storage affects price of electricity is likely unrealistically negative.

The cost it adds to the grid is the same in the game regardless of how much excess electricity production we have. But obviously large quantities of excess electricity can be sold at low prices even negative prices.

Let me try to explain. Building a storage solution requires capital. You got to borrow money at an interest. The cost of storage per week is then basically the cost of paying interest on this loan.

The owner has to make more money than they pay on this loan each week by buying electricity cheap and selling it at a high price. Then it makes a big difference how much you got to pay for electricity. At negative rates you get paid to buy the electricity. And massive excess production, you like pay 0 for the electricity while you can sell it back at relatively high price.

Written by

Geek dad, living in Oslo, Norway with passion for UX, Julia programming, science, teaching, reading and writing.

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