Written by Harold Armitage

 

 

The future is electric. With electricity, you can do almost anything.

It’s evident that renewable energy/electricity is going to play a major part in future electricity supplies. At the moment it ekes out our fossil fuel reserves, ie buys time. The problem of course is intermittency. There are solutions but costly ones.

It’s evident that as fossil fuel becomes depleted, hence more expensive, we are going to have to become more efficient in the use of energy, and also we have to reduce pollution. This is the interim plan to do this and provide energy security but eventually the gas too will run out and meanwhile we may fall into the hands of the Russians who are seeking to control the EUSSR by means of gas blackmail.
All fossil fuels can be burned more efficiently and with less pollution at large central power stations. The proposition is to use gas in the latest power stations which are twice as efficient as the traditional ones. Our gas comes from Norway by pipeline and from the Middle East by cryogenic tanker. In the future there is to be no gas supply to domestic homes, they will be heated electrically.

However, electricity is expensive especially if it’s derived from fossil fuel itself on an upward price spiral. Transmission is relatively cheap and efficient. Which brings us to heat pumps.

Heat pumps

By the use of refrigeration technology, it’s possible to use electrically driven pumps to transfer heat from outside a building to inside. With present technology, for every Kwh of electricity put into the pump you get 3-4Kwh of heat out in ideal conditions. The heat is transported with water which is of a much lower temperature than that of a traditional gas boiler. This means the radiators have to be much larger or underfloor heating is used. However, there are many practical issues. The heat has to come from somewhere, it could be the ground, a river, underground water, or even the air. Underground sourced heat is available year-round. Additionally, it’s possible to have reversible heat pumps and cool the house in Summer, ie heat can be pumped into the ground and retrieved in Winter, a more efficient arrangement. However, this is a very costly enterprise involving a lot of digging or drilling.

A cheaper alternative is to abstract heat from the air, this is the one usually adopted on grounds of cost. However as the air gets colder, less heat is available and the pump works less well. In very cold weather the pump may not work at all. The solution to this is to store heat in the fabric of the building. The “heat store” takes the form of massively constructed walls with external insulation or, more usually, underfloor heating with a massively thick concrete floor, well insulated beneath.  The residual heat stored in the floor is sufficient to keep the building warm for several days of cold weather.

There’s also the issue of where domestic hot water comes from, usually, some form of supplementary heat is required. All this costs money and there’s plenty of scope for cutting corners both in concrete (the floor thickness) or insulation (under the floor). The building itself needs to be well insulated, ideally with external insulation and draught proofing.

Heat pumps are not well understood by your average heating installer, more scope for cock ups. Another issue in the UK climate, the outside part of the installation (the evaporator) can freeze up into a solid block of ice in humid conditions so preventing proper operation.  This means a “defrost cycle”  is needed to prevent this. All adds to the complexity and cost. Fan noise from the exterior part  (evaporator) can cause complaints from neighbours.

Where the plans come unstuck

Whereas this is all fine in new construction where the work is properly carried out, we have millions of existing houses. Few lend themselves to retro-fitting heat pumps due to the traditional building construction and the difficulties/expense of adding exterior insulation. Less than 5% of existing buildings can be converted without major disruption and expense.

The minimal and cheapest “solution” sometimes employed is simply to connect the heat pump to an existing cenral heating system. This however is unlikely to be satisfactory due to much lower temperature of the water from the heat pump and lack of a heat store (larger radiators are needed). Supplementary heating will be needed in cold weather and also for domestic hot water. Sometimes an attempt is made to store heat in the form of hot water.  Unless the hot water store is very large, this is unlikely to work well.

Electric cars use around a quarter of the energy compared to ICE engines. Also, they can be charged at times of plentiful electricity.

All this means we could run four or five times more efficiently energy-wise compared with the current system. This however depends on massive capital expenditure, We will need many more power stations and a much improved electricity distribution system. It will take many decades to implement, thirty years at least would be my guess. Meanwhile, the cost of gas will soar as the rest of the world is bent on a similar plan.

Also, the Russians are trying to create an energy dependence on their gas for the purpose of political blackmail. It’s hard to see how the EUSSR can avoid this and it will affect us in the UK.
I believe we will see the first serious problems arising in the coming Winter.

Harold Armitage was a hospital engineer responsible for burning thousands of tons of fossil fuel. He was also an energy efficiency engineer.
His own house has a total energy bill of £600/year including road fuel.
He exports almost £3,000 worth of electricity annually.
His house uses no gas and no electricity for heating.

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