By Lucelia Rodrigues, University of Nottingham
I am an architect specialised in sustainable design. Through my work, I have met many people who dream of living independently from the national energy grid, dream of generating and owning their own energy. In fact, who wouldn’t want to spend less money and have a more reliable and greener energy supply? I would love to!
Is that possible? Of course it is. But very difficult in the UK. Difficult for most homes, even energy efficient ones, because of the need for heating to maintain comfort and the rising demand for electricity to power our ever improving lifestyles.
The potential barriers to have your home independent from the grid are many. For example, let’s look into the most popular way to generate energy at home: solar photovoltaics (PVs). If you were thinking to invest in PVs to try to reduce your reliance on the grid to a minimal level you could face the following issues:
Space: You may simply not have enough space to install enough PV. The Energy Saving Trust estimates that a typical 3-bedroom house in the UK would use over 3,000kWh in a year. This would require that you have at least a 4kW PV system size, which would require around 26m2 shade-free sun-facing roof space. This is assuming you consume everything you produce, when it is available (or you may need 4 times more!) – which leads to my next point…
Use patterns: your PVs would generate lots of energy during the day when the sun is out – and so are most of us. Most homes will use more electricity after the sun is down, when the PVs cannot generate energy and therefore there is a mismatch between when we have energy and when we actually need energy… If only we could store it…
Storage: yes we can store it. We have all seen the latest home batteries made recently available by a well known US car manufacturer. It looks nice, nicer and cheaper than the ones that have been available to date. But they are still expensive and rather large – whilst the average boiler is around 50x70cm, these nice newly available home batteries are around 80x130cm. I’ve heard once from someone I really respect “home batteries are rich men toys”. Perhaps he is right? I’ll let you decide.
Cost: well, not sure I need to explain this in detail. If you want to generate as much energy as you use at any time of the year regardless of whether the sun is out, you will need a relatively large capital investment and expect a long term return. Or longer if you go for a large PV system, and/or batteries. Grants and subsides help to overcome this but they are in short supply. It is also hard to get loans and some system may affect your ability to get a mortgage. I know. Sigh.
Now, before we all go into despair let me tell you about what we think is the solution…
Community energy is not new, in fact it used to be the norm. The Domesday Survey reported that in 1086 there was 1 water-powered mill for every 300 inhabitants in England – every community owned and managed their own energy. If you want to learn more about this you can check out a presentation I gave a little while ago available here.
But what is community energy? According to Community Energy England, it is “an all-encompassing term for groups of people coming together to reduce energy use, purchase, manage and generate low carbon heat and power”.
So, in simple terms, you get together with your neighbours to jointly invest on the infrastructure and jointly benefit from it. Together you can maximise the benefits of renewable energy generation through local use. If your home is generating excess energy when you don’t need it, your neighbour can use it. Or it can be stored for later use. The idea is to aggregate use and optimise energy flows based on demand variation, and make it cheaper for the consumer.
Because of economies of scale, the price of the infrastructure – such a PVs and batteries – will be cheaper per kWh. Controls can be used to optimise the best place for the energy to be – in your living room, in the community store or back into the grid – improving performance and cost-efficiency. One big battery is much more efficient than several combined, and it will also save space in your home. And it will give you opportunities to meet your neighbours and perhaps even lead to new initiatives…
So, how do we get communities everywhere to produce, own and manage their own energy?
There are some technical and economic aspects of community energy that still need further research and development. That is why we created SCENe (Sustainable Community Energy Networks). SCENe’s partners are working hard on overcoming the barriers for a wider uptake of community energy in the UK.
SCENe aims to create blueprints and business models that can be use in other developments and communities across the country. SCENe will ‘energise’ the Trent Basin community and share the recipe with everyone – so more of us can own and use cheaper, greener and more reliable energy.