Where does the energy come from?

Background

We have all got used to the way energy is now available but the generally excellent service is a product of the last 120 years’ effort, a major part of which has been the installation of a superb distribution system for what we refer to as the utilities – gas, electricity, water, and communications. The first two, gas and electricity, are the energy utilities and, in the last 40 years, there have been major developments  in the installation of a national and (later) international natural gas grid as the gas industry changed over from locally produced (and poisonous) towns gas to natural gas. At the beginning of the 20th century all energy production was indeed local, Mr Edison’s marvellous invention of electrical power being implemented by small and locally sited power stations for each town – country districts being gradually joined in over the next 40 years and a national grid being slowly built up.

Where do we get energy now?

The main sources are natural gas and electricity, supplemented at present by marginal supplies from heating oil, bottled gas and renewable resources such as wood and solar. These supplements are more important in the villages not covered by the natural gas network. Wind energy also provides a significant and increasing resource as we are reminded every time in Rye that we look out to the south east and  see the mechanical ballet of the wind turbines. I’ll refer to the main sources as conventional and describe them first, going on to the renewable resources later.

Gas

Our natural gas comes for the most part from the North Sea and, as this resource is gradually exhausted, increasingly from Russia and the Middle East. The build-up of the natural gas supply over the last 35 years was an extraordinary effort and indeed was a major source of the increasing economic wellbeing of the country after the oil shocks and coal strikes  of the 70’s and early 80’s. The big reserves near to our shores in the North Sea and in Morecambe Bay are now running down and large interconnector pipelines from Norway and from Norfolk to Zeebrugge are bringing in increasing amounts of natural gas. Indeed, the Norfolk-Zeebrugge 42 inch 100 bar pipeline can supply the whole UK gas demand on its own – if there are supplies available from Europe – and that increasingly means Russia, Azerbaijan and Iran.

These gas supplies are supplemented also by liquefied natural gas (LNG) shipments into terminals such as Kingsnorth in the Isle of Grain and Milford Haven. These come from much further afield such as Qatar, Algeria and Trinidad, the LNG market operating in similar fashion to the crude oil market. LNG is transported and stored  at about -160 degrees Centigrade in very expensive large tankers and storage tanks.

There is a  variation in demand day by day and season by season – the gas network deals with this by a combination of letting the grid pressure reduce during periods of high short term demand, abstracting gas from storage facilities –  exhausted gas fields in the Southern North Sea mainly –  increasing supplies from the main international  interconnectors (if available) and rapid gasification of stored LNG. The gas storage is then replenished during periods of low demand.

Note that the increasing international dependence for gas energy has a direct effect on our balance of payments as a nation and therefore our economic wellbeing. Gas is always thought of as a clean fuel – indeed it is – but burning it does add to our CO2 emissions – those emissions we are trying to reduce by 80% by 2050.

Electricity

Like many European countries we are fortunate in having a highly developed national grid, enabling varying power demand to be met without interruption. In the period from the 50’s to the 70’s the Central Electricity Generating Board (CEGB) did an amazing job of building a network of massive power stations situated near the coal fields for the most part and typically in capacities up to 2200 MW – indeed they built too many for the load at the time. These stations have lasted a very long time but many of them are near the end of their useful lives and are steadily being retired also to meet the Carbon Reduction Commitment and other directives on sulphur dioxide, nitrogen oxides and dust. Some of these stations will be converted to biomass but be run only as peak shaving operations in December, January and February to compensate for the intermittent nature of renewable sources.

The  biomass conversions (Tilbury is a good example) – burn waste straw for the most part but include materials like waste timber and broiler house chicken litter– typically done by mixing it with conventional coal or by itself. Other newer stations have been built to burn natural gas and these have been a major source of our success as a nation in reducing our carbon emissions so far – natural gas only emits about half of the CO2 that coal does for equal energy production. Some of the first generation gas plants are themselves reaching the end of their lives.

A major national strategy over a long period has been to reduce our reliance on single sources of energy – those of us of a certain age remember vividly the effects of the miners’ strike in 1974 on top of the oil shocks of the previous year. Who knows, if Iran decides to precipitate something in the next 12 months we could face a similar situation – but the wind won’t stop blowing or the sun shining. This was the reason why there was so much emphasis in the 1970’s on the building of a fleet of nuclear power stations at enormous cost. France indeed went much further than we did; our proportion of nuclear generation is about 16% whereas in France it is 77%.

What Resources do we have?

Nationally to meet the Carbon Reduction Commitment we have to build a large capacity of renewable energy power generation. The energy will come from:-

  1. Solar
  2. Wind
  3. Biomass

Additionally we still have all the conventional technologies linked together by our distribution grids. If we can remove the CO2 from the coal and gas burning for instance then these technologies will have a long future. Carbon Capture and Storage (CCS) is being developed to address the problem but, as an old process engineer, the thought of dealing with the enormous volumes of low pressure exhaust gas and stripping out enough CO2 to judge it clean, strikes me as a long and expensive development task to do it economically. Don’t expect much action for another 10-15 years.

A very authoritative forecasting White Paper has recently been published by Bloomberg New Energy Finance (http://www.newenergyfinance.com/free-publications/white-papers/) showing how the UK could meet the challenge of the next 40 years. One striking conclusion is that the overall electricity  demand will stabilise and renewable resources will play a major part in meeting that demand. By 2030 up to 58% of the total generating capacity is forecast to come from renewable resources in the UK

Solar

The rapid rise in wind and solar investment worldwide has stimulated very rapid technical development to the extent that prices for solar modules have declined by 50% in 2011 alone. The nature of solar technology is that it can be installed locally at an economic cost  – there is little cost benefit in large scale installations as has been historically true of almost all other power generation technologies. This is a key factor in looking at the possibilities for the district round Rye and opens up the opportunity for a community energy project to serve local needs.

Our area is one of the sunniest in the UK – remember the good-natured spat between Hastings and Eastbourne as to which is the sunniest resort. Solar energy is about 1000 Kwh per square metre per year and solar PV (photo-voltaic) panels currently have an efficiency of about 8-9% – about 90 Kwh/m2/year. If solar PV  energy were the only source of energy we would need 1,000,000 square metres of  panels, a square kilometre! Remember though that most of our energy demand is for space heating – and solar thermal panels heating water are a lot more efficient than solar electric panels – about 50-60%. Hence the popularity of solar panels to supplement your hot water supply.

We’ve got a long way to catch up – Germany has already installed the same solar capacity that we are planning nationally for the year 2025 and Italy, for all its economic woes, last year invested 4 times as much as we did on solar generation. The rate of increase is indeed very steep and, even with the recent Government brake on Feed In Tariffs, it will still be both profitable and attractive.

Wind

Wind turbine generators, on the other hand, do benefit from being of a certain scale – the justification for the Little Cheyne installation. This has an annual capacity of 165 GWh (a GWh – gigawatt hour – is a million KWh). It is a sobering thought that the annual demand for energy (gas and electricity) for Rye and the surrounding villages is about half that – when you see the turbines in operation about 50% of them are serving Rye and district alone. Compare that also with Dungeness which, when at full capacity, generates 25 times as much as Little Cheyne.

It is difficult therefore to see the roofs of the area sprouting large numbers of small wind turbines – they are noisy close-up – but when have you ever heard the noise from Little Cheyne? However, I think we will see more wind projects in future in the area and why should the community not take part as an investment partner in them – after all we have to look at them so we might as well profit from them.

Biomass

The district around Rye is a good growing area – Romney Marsh has had sheep for ever. The area has lots of water and solar energy – and biomass is the product. Wooded coppices have been a feature for hundreds of years, producing large amounts of charcoal up to the 19th century and supporting iron foundries as a result. Biomass represents stored solar energy, unfortunately a fairly inefficient process with only 1% of the incident energy being made available. On the other hand it is comparatively low cost to harvest if the land is not otherwise usable for agriculture. Are there some possibilities here?

Other technologies

The big drawback to  renewable wind and sun is that they are intermittent – the sun can go behind a cloud and the wind can drop quite suddenly – and a baseload backup must be there at all times to compensate for this because, with a few exceptions, electricity cannot be stored. Our biggest demand is always a winter evening in the middle of December and a large cold anticyclone over the UK so there is no wind – you still need to keep the lights on. We cannot be independent of the national grids for a long time yet.

I hope to explore these problems and other required  technologies a bit further in a later blog.

The mix

Our future energy needs can be met by a mix of technologies and sources – from the distribution grids and increasingly from local sources – because they can made available at economically competitive rates – and the community can profit from the enterprise giving us both an income stream and making us less dependent on national and international events. It’s an exciting prospect that I hope we can explore through the Transition Towns Initiative.

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