Wind Turbine and Hydro Electric Heating Systems using Thermal Storage Tanks
Welcome and thanks for taking the time to read my latest thoughts on thermal storage. I will be discussing what renewable energy sources can be used and why / how we should be more interested in storing electrical energy produced by renewables like Solar PV, Wind Turbines and Hydro.
We are getting larger numbers of people interested in storing energy, previously this has been mainly from Solar PV. Now we are receiving emails from across the uk about storing energy produced by small scale wind turbines and small scale hydro too. Gondwana Green Heat has been installing / designing / selling and commissioning mainly woody biomass, solar thermal and thermal storage heating systems for over 10 years now. This has always included using thermal stores to capture energy to use when required. We currently have 3 thermal storage manufacturers we use. They all have different expertise, specifications and size constraints. We offer thermal storage tanks for different heating technologies from 50 litres to 200,000 litres. We can also supply single Immersion heaters from 1.5 kw to 2000 kw for our thermal stores.
NOTE: Buffer tanks, accumulator tanks & thermal stores are all thermal storage tanks (they all store thermal energy).
Featured above are pictures of 2 small thermal stores during install.
OK basics first:
What is a thermal store?
A thermal store is a cylinder / tank used to contain a liquid to store thermal energy (hot water normally). They come in various shapes, e.g. cube, cylinder etc. They generally look a bit like a hot water cylinder. They can be tiny 50 litres or huge 200 000 litres or lots linked together.
What is a wind turbine?
A wind turbine creates electrical energy from wind.
What is hydro electricity?
Hydro used water to turn a turbine which creates electricity.
How do we use the electricity from a tubine, hydro system and solar pv system?
In most cases excess electricity created is sold back to the grid, which can then be sold to other home s or businesses etc. It can also be used by the nearby properties for electric heating and general electrical consumption. A thermal store can also absorb this excess electrical energy by heating the water within a thermal store indirectly by using a immersion heater, this is a bit like the element in your kettle.
How can we use all, or as much cheap or nearly free wind or hydro energy that we produce?
What we do is we install a thermal storage tank. The thermal storage tank is fitted with immersion heaters, a bit like what you have in a electric kettle to heat water. The electrical energy is converted to thermal energy. The thermal energy can be used for hot water and central heating, or even industrial processes. Hydro and wind turbines work best in the cooler months due to windier conditions and more rain fall, this coinsides with our heating season, meaning a correctly sized hydro / wind system could be enough to power or supplement your heating and hot water needs. In most cases a much smaller wind turbine or hydro plant output is needed compared with a conventional gas oil or pellet boiler system, this is due to producing energy all day during winter, not just when you want it.
If excess energy is built up in the thermal storage tank, when the thermal storage tank has reached its maximum temperature limit, you will then send excess energy either off to the grid, or alternatively excess thermal energy can be stored in thermal holes, thermal holes are slabs or cubes of concrete or lime crete under the building, they slowly release heat meaning less need for radiators or underfloor heating during the heating season. During the summer months when we typically produce less energy from wind and hydro we need less thermal energy to heat our homes and businesses therefor hydro and wind are perfect for year round heating as well as looking after hot water needs.
This image is a small cube thermal store with dhw coil built in, image compliments of James Perry of Aukenheath, Lanarkshire.
Can i put multiple heat sources into my thermal store?
Yes, we often install systems which have a small turbine / hydro system, but wish to have solar thermal for hot water use in the summer and a boiler stove or a pellet boiler stove. All this is possible and is not as complex as you may think, it’s all in the planning and experience coupled with a wee team of quality engineers.
Can we have a district heating system heating (heating more than one home)?
Yes you can, opportunities are endless.
Please see the simplified sketch as a example of a turbine thermal storage systems with radiators.