While reading up on architecture in Japan recently, I came across a technology that I hadn’t heard of before: the Ene-Farm. It’s a domestic energy system that is being used in Japan and so far doesn’t seem to be available elsewhere, and it makes me curious. What is it, and why doesn’t anyone know about it?
First – what is an Ene-Farm? It’s a unit about the size of a refrigerator that provides heat and power. It draws on the gas grid, turns the gas into hydrogen, and then provides electricity from a hydrogen fuel cell. The heat generated in the conversion is captured and used for heating or for hot water.
The unit itself is often set up to run off a solar installation, but it still uses gas as a feedstock, making it a kind of hybrid system for domestic energy. Despite the use of fossil fuels, there are a number of real advantages. The most important is that the electricity is generated on site, so there are no losses in transmission. It’s a whole lot better than generating that power in a gas-fueled power station and then getting it to the point of use.
Secondly, it’s very efficient. When the heat and power are co-generated, an Ene-Farm can deliver 95% efficiency – an impressive figure for any technology. For comparison, the grid in Japan delivers heat and power with 40% efficiency.
When you put this together, households running an Ene-Farm basically cut their carbon footprint from domestic energy in half. When combined with solar power, manufacturers reckon the savings are nearer 60%.
Another useful feature is that the Ene-Farm is a smart system that can run when needed, and then pause during times of peak demand. Households can save money by running it overnight and taking advantage of lower energy prices, and then using the power from the fuel cell during the day. It also helps to moderate demand, which is one of the big challenges when trying to incorporate renewable energy into the grid. The benefits aren’t just for the household running the technology – the more homes have an Ene-Farm, the easier it is to manage the grid.
Finally, because they have this mini-power station between them and the grid, households with an Ene-Farm don’t get powercuts. And that is the main reason why they have proved popular in Japan. Post-Fukushima, Japan began mothballing its nuclear power plants and there was an energy shortfall for a while. For those that could afford it, the Ene-Farm kept the lights on, and the government supported their roll-out because of the benefits to the grid.
That partly answers question two, the question of why we don’t use these ourselves. The Japanese government has supported hydrogen fuel cell technology, with Ene-Farms just one small part of that. The decline of nuclear power in Japan has driven a search for new solutions and greater efficiency. So there are incentives, and a sense of urgency around energy efficiency that we just don’t have in Britain. Japan essentially switched off a third of its electricity supply in 2012, gas took up much of the shortfall, and anything that could reduce transmission loss and get more out the system was actively encouraged. Ene-Farms are part of Japan’s unique energy story.
Will we get them eventually? Maybe, though they won’t be called Ene-Farms. That was a nationwide branding exercise to raise awareness of hydrogen fuel cells, and is unique to Japan. But I suspect we will get domestic hydrogen fuel cell systems one day. We need solutions to renewable heat, we have fairly dramatic transmission loss statistics, and there’s a real carbon saving to be had. They could well be useful – especially if we can combine them with green gas. As far as I’m aware, so far this form of micro-CHP has never got beyond field trials in the UK and Germany.
The next generation of fuel cells, that Panasonic and others are working on, won’t use gas and will be effectively zero carbon. They probably won’t do heat in the same way, but will function more as domestic energy storage to complement renewable energy, and that’s where we are most likely to encounter them.