Interview with Rupert Blackstone

29 Sep 2022

Hello! I’ve wanted to do this for a while, and it’s happening - I did an interview. Just before term started, I was lucky enough to speak to Rupert Blackstone, Managing Director at Wattcraft which is a renewable energy consultancy. We spoke about his process, national policy, and costs.

There’s also a lightning round this edition, because I have things to tell you about!


Read the full interview here.

Rupert Blackstone is an energy consultant and chair of the Institute of Mechanical Engineers (IMechE) Environment, Energy, and Sustainability Group. To be a professional engineer you have to be part of an organisation like the IMechE. The group’s role is mostly educational. I’ll let Rupert explain.

RB: One of the main objectives is educational. The Environment, Energy, and Sustainability Group is a committee that is promoting sustainable engineering. We do this through a series of about 6 webinars we put on a year. We also make a newsletter and sometimes get involved in responding to government consultation on relevant topics. Within the group there are people who are in different sectors - energy, waste, water, transport, manufacturing, etc. - which is great, because we can develop an integrated approach to sustainable engineering. Sometimes we’ll contribute to seminars which other groups are putting on.

Even though the Environment, Energy, and Sustainability Group is relatively small scale, it’s good to see their work in education and especially in gathering together people from across a whole variety of sectors. In fact, they recently produced a report on community energy projects. But, before we can talk about that, we need to talk about demand reduction. Why? Well, because when thinking about being more renewable and sustainable, there is an energy hierarchy that helps prioritise the options. It goes something like this:

  1. Reduce demand
  2. Energy efficiency
  3. Renewables

Demand reduction

So first, why is demand reduction at the top of the hierarchy?

RB: I always apply the energy hierarchy in my work and prioritise reducing demand before looking at renewable energy. That’s partly because renewable energy is constrained. If you think of the UK, we’re very blessed with a good renewable energy resource: we’ve got a lot of wind, we also have a tidal resource, and a wave resource, but wind is the big one. But, even in the UK it’s a challenge for renewable energy to supply our current projected levels of consumption because people are resistant to onshore wind. This government particularly so, which, I should say, isn’t representative of people in general. […] Most Brits support wind according to polls. The pushback [from the government] makes it more expensive, since we end up building offshore wind and, as you go further offshore, it gets deeper, requiring more expensive structures, and further from shore more electrical cabling is required. So, it’s constrained quite significantly.

I was also curious about how much of a project’s impact demand reduction tends to make up and how feasible changes are.

RB: Usually there are opportunities for low cost energy consumption reduction through improving the controls, particularly heating. You can do it with lighting as well through occupancy sensors - people go out the room the lights go off. What we tend to find with heating is that someone might have fiddled with the controls, and then they were left for some time. You might have heating for 24 hours and you just don’t know about it. When you analyse the energy consumption data or log temperatures, you can see that there’s heating at night and do something about it. People often have heating [turning off] too [late] and - say they leave the building at 18:00 - they might have it switching off at 18:00 whereas if you turn it off an hour earlier, or a certain amount of time earlier, there’s still thermal mass within the building. So the building is kept at an acceptable temperature till people go. Temperature control is also important because often places are overheated and each degree of temperature turned down on the thermostat will have a significant impact on reducing heating consumption. So, those are the easiest ways to lower cost.

When it comes to insulation, then that starts to get expensive. Roof insulation can often have a payback on investment over a small number of years. Wall insulation is very expensive and it’s not generally regarded as having a payback or at least not one that’s economically acceptable in most cases.

Speaking of reducing consumption like this, Winchester College has a lot of potential for energy demand reduction. Fortunately, WinColl, for some reason - surely environmental - has suddenly started to care a lot more about its gas (and electricity) use. There are some obvious issues, like that fact that to heat the corridor of power you have to heat the whole of flint court, even when it’s not being used on half-rems, which are looking to get fixed, as well as changes that require a little more thought, like exactly when hot water needs to be available. In a welcome shift from the norm, it looks like the college will be in close consultation with pupils throughout the process too.

Next Rupert discussed the general process in projects he works on and how demand reduction ties into that:

RB: On projects I’ve worked on, often what I do for clients is compare different energy improvement measures. I’ll include: energy demand reduction, energy efficiency measures, renewable energy measures, and do life cycle cost assessments of those which looks at the cost of implementation, any maintenance over the life cycle, and then balances that against the saving money over the life cycle, taking into account capital costs, operation costs, operational savings, and energy cost reduction. When energy demand reduction measures get more expensive people are likely to go for the renewable energy option. If I can give you an example of biomass heating, there used to be government support for that - the Renewable Heat Incentive. By applying the renewable energy hierarchy, we want to focus on insulating the building. You don’t want to be heating a building that’s leaking loads of heat, wasting biomass, and it’s too expensive as well. You get diminishing benefits with insulation: if you double the thickness of insulation, you don’t halve the heat loss because of the thermodynamics. Even just the fixed cost of any level of insulation is quite high, so there’s a balance to be made between how far do you insulate a building and at what point do you say “well, I’m not going to be able to insulate it, so it doesn’t need any heat, so I’m now going to size the biomass boiler for this level of insulation.” If you go to passivhaus standard with residential, you pretty much don’t need to heat the building, because you’ve got solar gains and internal gains, but that’s very expensive, so in most cases so it would be cheaper not to do so much insulation and have more renewable energy. There’s an economic decision there.

Recently we’ve seen unprecedented energy prices, and individuals and corporations are making changes to adjust to these changes and prepare for future volatility.

RB: [Demand reduction is] about resilience too, because the more you do energy demand reduction, the less energy supply you need, the less exposure to the volatility of the energy market you have. In the UK, renewables pricing is linked to fossil fuel pricing because the price that everyone pays is down to the marginal cost of the most expensive energy generator. Renewables are making a lot more money now because of gas prices. That’s just the way the market is at the moment. So whether it’s renewables of fossils, at the moment it’s very volatile, so it makes sense to minimise your exposure to the market with demand reduction.

Despite this, we haven’t seen much concerted messaging pushing people to reduce their energy consumption. This seemed weird to me, as it’s an obvious first step, and probably necessary if we look realistically at supplying energy to Britain this winter. So I asked why we haven’t been seeing that kind of messaging.

RB: I think it’s largely political. For example, our building standards are much worse than those of other European countries, but the building developers lobby the government and they have a lot of influence and […] a lot of them are donors to the Conservative party. It applies to different degrees to all parties probably, but certainly under David Cameron’s government there was a watering down of the building regulations in the code for the sustainable homes (not the emissions targets). I think it’s vested interest since what we’re exposed to in our energy prices really doesn’t make sense. I suppose it is because of a failure of government to do anything about this. Now Liz Truss is saying she’ll remove the green energy tariff to help people pay their bills, which is only £150/year, and the only reason we have the problems with bills is because of our dependency on fossil fuels. It’s just madness. The problem is it all gets political.

Community Energy

I wanted to talk to Rupert about community energy for a couple of reasons. First, I had been reading about it in Drawdown and heard about it in other places; community scale energy projects could offer greater flexibility and resilience for communities, especially ones which are relatively cut off from the grid. The other reason was that he had written an article and the Environment, Energy, and Sustainability Group had written a report about it relatively recently. Here’s what he had to say:

RB: The good thing about community energy projects is that they get people thinking about their energy. They make people think through what implementing renewable energy means in practice and think about energy demand. This helps build an understanding of what it to means to transition and what the challenges and other benefits are.

Those are the upsides, but it can only really be - I believe - a relatively small contribution. A successful community energy project requires a lot of enthusiasm and people with a lot of time to give to thinking about energy systems. Relatively few people work full time on a community energy project. It’s mostly people working part time. Community energy projects are not necessarily replicable across the country, since it’s not necessarily the case that where people live is the best place for renewable energy generation: consider wind energy, it’s best on top of a hill in a remote place, generally away from people. That’s not the sort of things communities have access to. Sometimes there are benefits for economies of scale with certain types of renewable energy which can be a disbenefit of community scale generation.

Project Drawdown actually doesn’t quantify the impact of community energy projects because they’re included as necessary steps in building renewable energy infrastructure. I think this is a sensible way of thinking about community energy projects as well some aspects of the next thing we talked about, energy storage (although the impact of raising awareness and bringing communities together should not be underestimated).

Energy Infrastructure

First I asked about small scale energy storage. Whilst battery prices are falling rapidly, they’re still expensive and require mining for transition minerals which causes many of the same problems as mining for coal (for example).

RB: I think [small scale storage] will [play a significant role]. It will need to, because sometimes renewable energy generation might be appropriate at the far ends of the distribution network. The network has been designed for one way flow of electricity, so it’s like a tree: you’ve got a trunk and branches and leaves and it gets thinner and thinner. This means that there is less capacity at the end of the network. If you want to get renewable energy generation at the far reaches of the distribution network, you either have to upgrade the network or create local storage and that’s often a commercial decision. There is storage on a national scale which will help with balancing the intermittency of renewable energy as the dominant renewables in UK are wind energy (mainly), and solar. The problem with solar is that there is an interseason mismatch between supply and demand. There is the highest generation in the summer and highest demand in the winter. If you meet your winter demand with wind energy, that wind energy resource is still going to be there in the summer, so the question is how much PV is really useful at scale. PV is more predictable than wind energy, but it’s still intermittent. We need a combination of storage and demand management. That would mean switching off loads when the energy supply is low and switching things on when the sun is shining or the wind is blowing. Interconnectors with other countries are also an option, because the more renewable energy you have across the continent, the lower chance of periods when no wind blowing. Most of the time, there’s wind energy and solar to some extent. The more you interconnect, the more balanced the supply is, so I think energy storage locally and on a large scale is a good thing.

I think the point about the distribution network is crucial. Adding all the infrastructure required to integrate renewable energy which is being generated where there isn’t much energy infrastructure is expensive and difficult, it’s easier if you can skip doing that and use as much as possible at a local level.

Speaking of costs, there’s a few different opinions about the costs of renewable energy, so I decided to ask Rupert about it. During this bit, we ran out of time on our zoom call but I’ve filled in the last sentence for him.

RB: I can’t answer with certainty in all areas. The thing is that costs are varying so wildly at the moment it’s hard to get an understanding. Wind energy is the cheapest form of electricity generation in this country, although to what extent that takes into account the requirement for energy storage and energy demand management, I couldn’t say for sure. There have been studies that have taken that into account. You can’t just look at a wind turbine if you want to have wind energy, you’ve really got to have some sort of balancing infrastructure with the generation. Anyway, wind energy is a very low cost form of electricity generation relative to alternatives. It’s projected that PV projects will be cheaper than many fossil fuel projects. Some people say solar is cheaper than wind, but it’s not in my experience because, per kW the capital cost is comparable with wind, but you don’t generate as much energy over the year with PV as you do with a well sited wind turbine. PVs are getting a lot cheaper, so there could be some sort of convergence there. For biomass: wood fuel tends to track oil; wood pellets are also similar to the oil price per kWh; and wood chip tends to be a bit cheaper depending on where it’s from. However, an actual biomass boiler is more expensive than a gas boiler, so life cycle costs without any support are higher than the fossil fuel equivalents for biomass heating and the same generally applies to heat pumps. It might be that it’s changing with electricity prices changing - I don’t track it every week or even month. One important thing to note is external costs; often the economics are misleading because fossil fuels don’t price in the externalities. [inserted by me since the call cut off] Deciding on a fair price for emissions is hard, because accounting for (potential) damage repairs is hard, so economists tend to ignore that and call it an externality, which can create misleading results.

The point about externalities is really important. Most of the time, anybody arguing about the costs of renewables is probably counting human suffering and deaths as an externality. This gives economists a fancy way of saying “it’s complicated so I’m not pricing it in.” That said, reducing costs is really important in getting things up and running quickly and it would be silly to deny that.

Will to make changes

There are ways to logic around sustainable things being more expensive, one way is just for all corporations to care about their impacts on people and planet but that just happening spontaneously is unlikely at best. However, Rupert did talk about one more realistic way companies are exerting pressure to become more sustainable.

RB: What’s happening more often now is that organisations are focusing on getting to net zero greenhouse gas emissions in line with the government target of getting to net zero by 2050. A lot of pressure for that to happen is not yet through regulation, but big companies are signing up to science-based targets for emissions reductions. When trying to reduce their scope 3 emissions, they apply pressure down the supply chain. For them to get to net zero, you need their supply chain to be net zero. So for companies now, it’s not just about making cost savings in relation to energy costs, it’s also about potentially missing out on contracts with customers. In the tender process, companies are expected to commit to getting to net zero and maybe sign up to a programme or standard or initiative of science based targets; this way they have a formal commitment to the target to get the contract. What that means is that the value of the contract and the potential loss of business from not getting the contract can be far greater than the energy cost of implementation of sustainable energy measures. Now corporations might put in more insulation, and it might not have a payback in terms of energy savings, but if it means they can get towards net zero and get the contracts through the tender process then it could be worth doing.

Hope you enjoyed the interview! Of course huge thanks to Rupert Blackstone for giving up his time to speak to me.


Lightning Round

Inflation Reduction Act

Some of you may have noticed that a certain “Inflation Reduction Act” has been passed in the US. This is huge good news, and what’s even better is it’s pretty hard to undo once Biden’s gone because it’s just giving out money. Hank Green did a really good explainer video: The Biggest Climate Bill of your Life - But What does it DO!?

Motivational Interviewing

Motivational Interviewing can literally save the world - Jen Read, PhD Clinical Psychology

Vince Schutt from Environmentum is will be giving his Motivational Interviewing course to Winchester College. It would be great to have lots of people sign up (although I’m already pretty happy with numbers).

Vince knows a whole lot about behavioural change and believes it is an essential part of an environmental transition that we don’t put as much effort into as we should. He has evidence too: after he gave his Motivational Interviewing course to CCL Canada, Canada became the first country to institute a Carbon Fee & Dividend policy. Perhaps we focus too much on economics and how to make things work assuming nothing changes, and we could focus more on how to influence people in a way that emphasises their autonomy and listens to them.

Environmentum’s mission is “to empower environmental and social justice change leaders with evidence-based communications practices for cultivating change in their communities and to grow the capacity for individual self determination from micro to macro scale.” They are great at this.

I highly encourage you to sign up and come to his course. It will be awesome and he tends to tailor each session to the specific audience.

Sustainability Society

We are super busy this term and have an ambitious plan that so far we are sticking to well. There’s space for you to run your own projects or help in any of our existing ones, including writing for The Climate Soup! Some of our planned projects include:


What’s the monetary value of human civilization? Trying to answer that question proves you are a moral and practical idiot. - Kim Stanley Robinson in The Ministry for the Future

An interview’s a new thing for me, and I’ve lots of progress to make both in interviewing and in writing those up; feedback appreciated. Thanks for reading and hopefully see you next week!

See you next edition,
Oscar Mitcham