The UK Government has announced that it no longer wants to subsidise solar power and that they are thinking of stopping the Feed-In-Tariff scheme completely from April 2019 (people already in the scheme are fine). This is an amazing turnaround from the high subsidies that were offered only a few years ago for solar power, so why the change of attitude? Is it completely due to the claimed price reduction in home-PV that makes the Government feel that it doesn’t need to subsidise it anymore, or is there something deeper, perhaps darker to it?
Many years ago when I worked as a solar power researcher, my colleagues and I dreamed of a day where PV solar power would be cheap enough to be used by everyone, everywhere. The electricity is free (once you've bought the system), it's renewable and has a very long working life (many might last half a century or more I reckon). Fast forward a few years, and now I look around and those days are actually here, and PV solar power is available to all, I should be over the moon. In the past though, I didn't think much about any of the consequences of our success, I thought they would be lesser problems that we could sort out later. With success as an industry now here, we are getting to meet those lesser problems face to face.
You may have heard about instability issues with solar power before, it’s described as ‘intermittency’. In short this means that sometimes you will have periods where you are generating solar power and some periods where you are not, but you can never really be sure when those periods will be. And this is the problem when designing a national grid, not knowing when there will be power available is a real headache. The instability issues with solar can be summarised like this; passing clouds, cloud cover and Winter. Passing clouds cause a temporary dip in output power that needs to be covered quickly by the grid. This is called frequency response, and right now is covered by the giant spinning turbines of our gas power-stations. In future, we want to turn off those power stations, but we can replace them with large banks of fast acting batteries to do the job instead. More serious is cloud cover, this will also require in the future more batteries, this time set-up for a longer and consistent power draw to top-up the missing solar power. The third-problem, Winter, well there is no fix for that. The grid is going to need replacement and temporary power stations somewhere to generate the extra power to make up for the loss in solar power during the Winter.
For solar power to be acceptable to the grid on a large scale we are going to need the above extra infrastructure and this extra infrastructure is likely to cost extra money. So, who will pay this potential extra cost? Presumably all of us, by an increase in our standing charges or maybe an increase in the cost per unit of electricity. This all sounds reasonable and fair until we realise that those with solar power get cheaper bills by self-generating, but everyone is paying for the extra infrastructure to make this possible (not just those with the solar power). So, having solar power gives you a double discount, you don’t pay for having power, and you don’t pay for the extra infrastructure upgrades needed to facilitate solar power.
This is a real dilemma, solar power is great for the environment and we can’t get enough from that perspective, however as a society it’s more difficult, everyone else pays an extra burden for some to have solar power and the more people there are with solar power, the more cost needs to be spread around those who don’t. And not everyone can have solar power even if they want it, the young and the poor are hit hardest because they can’t pay the upfront costs of buying solar power or just don’t own a house to begin with.
From this societal perspective, I can see a reason as to why the UK Government has decided to stop the Feed-In-Tariff programme and to stop subsidies. People should still be able to buy solar power and enjoy the benefits, but they shouldn’t be given subsidies to do so.
So solar power has two faces, a good side and a bad side, and we need a tweak in the system somewhere to re-balance the two. I was knaive in the past to think that solar power was the complete answer, instead (as always) it’s only part of the puzzle. There are some forms of home self-generation that create no problems with intermittency and so don’t cause a burden on the grid and these should still be promoted. I think particularly of technology that I currently work with everyday, engine or fuel cell heat and power systems (called mCHP). That these systems are being caught in the Government retreat on solar and are also losing their subsidy is a set-back, but their potential is great and a reason to look forward to the future.
In a previous post I talked about a lot of websites or apps that will show you the average carbon emissions for the UK grid and use this as a guide to when you could use your energy-hungry electrical appliances. The problem I have is that most of the traffic light systems based on averages are actually misleading. To make a decision to run an energy-hungry appliance or not, you don't use an average, you need to look at the marginal cost of producing that extra electricity to run your appliance.
Let's look at this in more common business terms. The marginal cost is used to describe the cost of producing one extra unit. Economically, things tend to get cheaper to produce per unit as you produce more and more of them but that after some number of units produced, the units actually get more expensive due to dis-economies of scale (you need a bigger warehouse, pay staff overtime, a complicated computer system, communication errors etc). In our case, the marginal cost can be described as the cost (in carbon) of producing 1 extra gigawatt (GW) of electricity for the grid. For that extra GW of electricity, the carbon emissions cost will depend from where that electricity is sourced. Intermittent electricity sources such as solar and wind cant contribute as they can't produce any extra to meet demand, that's not how they work, and nuclear is nearly always maxed-out due to the economics of investing in such high-cost power. This leaves natural gas (or fossil fuels in general) as the marginal generators in the UK electricity grid most of the time. This means that the marginal cost of electricity production is nearly always the cost of making a gas-fired power plant work harder (roughly 400 metric tonnes of CO2 per extra GW or more).
You can go all-out on this kind of analysis and use machine learning and other mass data analysis techniques to churn out a number on the marginal cost, and this is what the people at tmrow.co have done. But whether you just look at the grid in a simple way or look at all the data, the answer is the same, for the UK it's usually gas-power stations as the marginal generators of electricity. All of this is no surprise, there are lots of sources available on the web that talk about the marginal cost (described as the marginal or displacement emissions factor) of electricity production, so it seems strange that websites with traffic lights don't take account of this or at least mention it (kudos to Earth Notes for doing so).
So, sadly, there is currently (2018) no obvious best time to run your dishwasher to reduce your carbon emissions. The best way forward is to still use your dishwasher or washing machine as effectively as possible (full-loads and at a low temperature). On a positive note, the high cost of marginal electricity production is a good thing when you are trying to reduce carbon by energy saving. Any energy we use comes at a high marginal carbon emissions cost and so energy saving has a large carbon reducing effect. In fact energy saving is by far and away the best method of achieving all the goals of our energy revolution, making energy cheaper, greener and more reliable. Every bit of electricity saved (electricity nega-watts), means a customer doesn't have to pay for it, there are fewer carbon emissions in making it, and the electricity grid doesn't have to be upgraded to carry it. This is the reason for my whole website, there is no downside to energy efficiency for anybody.
Finally, I would be bad if I suggested to consumers that you can ignore grid 'signals' and to use your energy hungry appliances whenever. In fact, I believe the opposite, and that we should start opening up to the idea of relying on signals on when to use our biggest appliances. This is because time-of-use electricity pricing is almost definitely coming, so using your energy-hungry appliances at peak times is going to get more expensive.
Solar Power, like coffee, is performance enhancing; but you have to know when too much is no longer having an effect. And by this I mean, it won't have the carbon reducing effect we all want it to.
This week came the news that almost certainly all new homes built in the state of California, will have to have solar photovoltaic (electricity generating) panels on their roofs after 2020. Given the state is famous for it’s sunshine and electricity shortages, this would seem to be a no-brainer decision. And in many ways, it is. Electricity use in the U.S.A. tends to go up in summer when the sun is out, because of the use of air-conditioning to cool homes. That means solar power and power use at home are sympathetic, and home-owners will save energy and money, even when you consider the higher mortgage cost to fund buying the panels.
The UK however is not California. When the sun is out in the UK, the electricity grid demand is typically at its lowest, as people turn-off their heating and lights, and go outside. There is nothing better than a British summer, as the saying goes. As in California and elsewhere in the World, many new UK house builds are coming with solar power panels on the roof as a means to pass Government energy regulations, that themselves are set to reduce carbon dioxide emissions and halt climate change. But if the UK home-owner isn’t indoors to use that electricity then who is using it? Well the answer is that the grid is using that energy, and very grateful they are for that energy, to power factories, offices and shops. With home-owners over a year only using around 35% of the electricity they produce from their solar panels (Source: The SolarBlogger) a huge 65% of the electricity ends up on the electricity grid. In a balancing act this surplus sunshine causes gas-fired and other fossil fuel power stations adding to the grid to shut-down, meaning the electricity grid becomes less carbon intense and more ‘green’. This is great for our carbon targets but can cause the paradoxical situation where we have too much electricity on the grid. But that isn’t the only issue, another issue is that it causes us to ‘overestimate’ our carbon reductions. With every new set of solar panels that are installed on roofs around the country, the amount of carbon dioxide they are actually displacing goes lower and lower. This year the fossil fuel stations may be off for only a handful of gloriously sunny days over the year, but in a few years time they may be off when it’s overcast. At this point, any extra solar panels that we add to the grid don’t reduce any of our carbon emissions, as there are no more fossil fuel power stations left on the grid to disable. The electricity has no carbon reduction value, whatsoever.
However, if we continue as we are adding solar panels to the roofs of the 100,000’s of new homes we are building around the country, all in the name of carbon reduction, we won’t actually be achieving any, or at best not as much as we think. Don’t misunderstand me, solar power is a great thing, and every home owner should consider solar panels, but once we pass a certain point with the grid, we are not reducing carbon emissions, we are just pretending we are.
The problem is in the way that carbon emissions are accounted for, especially in new build homes and in the giant excel spreadsheet which is called, the Standard Assessment Procedure (SAP). In this document electricity produced by any home with self-generating technology can create ‘carbon’ credits, that can then be drawn down over the course of the year. By this method you can have a net-zero carbon home, the emphasis here is on the ‘net’ part, meaning your self-generating technology has generated more electricity than you have used over the course of the year. In the case of solar panels, this means your panels have produced more electricity in the summer than you use all year round. And therein lies the problem, when solar panel power was guaranteed to reduce fossil fuel power plant emissions, you were indeed reducing carbon emissions in the summer, to cover what you were producing in the winter. However, as more solar power goes onto the grid this no longer holds true. Additional Solar power exported to the grid could have zero effect on the carbon emissions throughout the summer, thereby not offsetting real carbon emissions in the winter. This means we think we have reduced carbon, whereas we actually haven’t, it’s just an accountancy error. Taken to the extreme, we could have every house in the country with solar panels, producing a huge amount of ‘credit’ in the summer, but this doesn’t make our carbon emissions from our heating in the winter disappear.
The SAP could adjust, it should adjust. It could either place hard limits on the number of new houses that can be built with solar panels or reduce the average carbon saving of every house with solar panels. The former suggestion is sensible and makes a gap for other energy saving technology to flourish, but seems rather harsh and clinical, while the latter has a flaw in that developers might react to a decreasing carbon saving per panel by just putting more panels on, thereby accelerating the problem. Metaphorically, it is like coffee addiction, you either decide to limit your caffeine intake so you can enjoy the buzz, and give you space to enjoy another type of drink during your break, or you can just keep drinking more and more in the hope that it’s still making a difference.
So how do you to become familiar with the UK's electricity grid? You need some data, and luckily there are some brilliant websites out there that can show you what the grid is doing all day every day.
Gridwatch also has a similar webpage for the French Grid that is equally informative, mostly because the French grid is so different to ours and it can tell you a lot. Gridwatch GB's best feature by far however is that it has archived all the data since 2011, providing a valuable resource for data analysts, professional and students alike. I know I will be using this resource for a future blog post but sadly, this treasure trove of data and the website itself is under threat as the website owner struggles with financing. I urge those that can donate to do so.
Here you will find my thoughts on my work, my energy saving projects at home, or just commentary on changes happening to technology or the UK electricity and gas grids.
Usually energy and energy grids are discussed negatively; we need to save energy, reduce energy use, make energy more expensive or avoid calamity brought about by climate change. Hardly anyone has anything positive to say about energy and this makes it hard for people to become motivated to get behind changes to our energy systems. So here we want to talk about changes to energy and our energy ecology in a positive way, because the fact is that the changes we are seeing to energy and energy technology are radical and clever, and once you see that, you too will feel positive about energy.
About this blog
I have been involved in the field of energy for nearly 20 years, so I have a deep relationship with the subject.