On 28th Jan we gave a presentation on heat batteries to Reading U3A’s Science and Technology group.
Heat battery technology has the potential to transform the way we heat our buildings and our hot water supply. Batteries decouple the time at which heat is needed from the time at which it is generated. They are more compact and efficient than hot water tanks.
Heat batteries can store energy from any kind of source, such as a heat pump, a biomass boiler, solar panels or cheap-rate grid electricity, and save it until we want hot water in the mornings and warm rooms at night.
Click the link above to see the slides. You should be able to comment on them.
The UK yesterday (29th Jan 2020) reached a milestone in tackling climate breakdown.
Over the year beginning 30th Jan 2019, electricity generation for the UK grid produced carbon dioxide emissions of 184 grammes per kilowatt-hour. (Figure from Drax Electric Insights)
184 g/kWh is a milestone because it is also the amount emitted by burning natural gas. Thus UK electricity is now as “clean” as gas, on average, and becoming steadily cleaner. Exactly five years previously, the annual grid emissions were more than twice what they are now at 412 g/kWh.
We owe this progress mainly to generation from coal having been almost phased out, many more wind turbines being installed, and overall electricity demand having fallen as we moved to energy efficient appliances. Plus a few relatively minor contributions.
Celebrations should be muted and symbolic, because gas is still a cheaper fuel than electricity and therefore we use four times more of it, mostly for heating rooms and water. Nevertheless, we have shown the world that things can be changed on a grand scale faster than might seem possible.
What should be the next target? It is possible to switch from gas to electricity for direct hot water (i.e. taps and showers, not room heating). Two developed technologies are available. Basic heat pumps can heat enough water and compact heat batteries can decouple the time of use from the time of heating. This decoupling lets us use overnight grid electricity and solar panels – both are competitive with gas – and also reduce the massive morning and evening peaks in gas demand.
When? Five years seems suitably ambitious for a climate emergency.