Combined Heat and Power

A description of the project, its background and the current status
Power generation in England contributes to a sizable proportion of the countries CO2 pollution and fossil fuel consumption, making it crucial to invest in technologies offering positive change such as Combined Heat and Power (CHP).

CHP: the act of simultaneously generating both heat and electricity, achieved by producing electricity conventionally whilst capturing and utilising the ‘normally’ unwanted heat. Heat capture is performed slightly differently depending on the system, but almost all variations transfer warmth through the use of super heated water, boiled by the phenomenal temperatures reached within the generators. Once ‘ferried’ to its destination the heat is utilised within homes and offices amongst others depending on the systems location and design. By consuming this primary byproduct, efficiency can potentially soar from 40% to 95%.

Micro (small scale) CHP technologies, are by far the most common systems installed within the UK, one in the final stages of development is the WhisperGen product developed by Powergen. A unit, roughly the size of a fridge caters for a households heating and hot water needs plus the majority of there energy needs, with conventional electricity being used when the demand cannot be met.

The main aim of these units is to utilize fuel in ‘greener’ more cost effective manner. This has been proved as the WhisperGen product passed through many field trials and feasibility studies over the last few years. Efficiency has been measured at over 90%, financial savings at 19% and carbon savings upwards of 16%. With such positive results it is no surprise that Powergen are continuing “Commercial tests” throughout 2008, with the vision of a “full market roll-out of mass-manufactured units from early 2009”. Such a roll-out is a hugely important step in the push for change.

Possible alternatives
Considering our predominant world status and wealth, the UK has an extremely old, inefficient and unreliable electricity network. In the 1970’s the oil crisis gained the worlds attention and while others invested in changing there power networks, the English government simply sourced fuel from elsewhere. With this obstacle solved, our mass power plants have undergone little change within the last 50 years, continuing to pump out un-forgivable levels of pollutants, as well as the staggering inefficiency levels. Between production and the consumer 2/3 of the energy generated is lost, with the heat (currently completely un-used) being pumped into the atmosphere or lost through the cooling systems and a sizable portion of electricity being lost as heat along the transmission pylons. Once reaching its destination consumers then create more pollution when the energy is actually put into use. This waste is enough to meet the energy demands of every household in the UK, with such staggering facts it is easy to see why the ‘greener’ minded people are pushing for change.

If we look at some of our European neighbors, for example the Netherlands and Denmark, while Britain took to sourcing fossil fuels from elsewhere. These countries took this shortage as an opportunity to seek new, cleaner alternatives, this gradual change over time shows a somewhat embarrassing contrast if compared to systems within the UK at present.

Within the Netherlands over half of the countries electricity and heat demand is supplied by CHP plants. They have successfully de-centralised the majority of their power plants, resulting in a vast network of ‘mini’ power stations. With each ‘mini’ power station serving a group of houses or a tower block for example. Having these generators situated in the centre of there service zone immediately doubles efficiency which is obviously a positive step for everyone, plus if a technical problem arises, only a relatively small number of consumers will feel the effects.

Small scale plants are uncommon within the United Kingdom, such de-centralised setups offer many advantages the main being the close proximity of the producer and consumer. This also overcomes one of the main disadvantages of the WhisperGen system which function at peak efficiency in larger houses, which is important considering the huge proportion of the population live in flats, 2 and 3 bedroom dwellings.

Currently there are huge power stations using the ‘CHP principal’ across England, this is obviously an improvement on our current setup, however the main disadvantage is that CHP requires expensive super insulated piping to transport the heat, meaning such setups as stated above are best suited to locations close to the consumer. Meaning it is rarely practical for such sites to serve residential housing, but these setups could be used to supply dense office complexes or industrial processes for example both of which have a huge heat demand considering there geographical area.

An improved setup to that above are the huge CHP bio plants in Denmark, these setups use a mixture of biomass and standard non-renewable fuels, added in the smallest quantities possible to achieve the necessary boiler temperatures. These setups have an incredible 95% efficiency, using pulped biomass which is totally free: as the straw would have been burnt by farmers and the wood normally just scrapped. As well as using far less non-renewable fuels, the biomass used is carbon neutral, meaning the carbon dioxide produced when burnt equals that consumed by the plant over its lifetime in photosynthesises. The final main advantage is the lower level of pollution and the toxicity of pollutants produced when the ‘biofuel’ mix is used.

The political and financial effects of this project.
The Government has a huge range of ‘tools’ which could be used to massively influence the push for a ‘greener’ Britain, the effect could potentially stretch to a global level as more countries see the success and advantages. Such incentives could include cheaper gas for use in CHP systems, a quicker planning process for CHP power plants, subsidised equipment and advertising. Heavy investment could ploughed into general CHP technology and the companies which will advertise, produce, install and maintain the CHP systems. Another possibility is the controversial path of ‘fining’ the most damaging fuels and setups.

Many of the options above are successfully in place abroad, highlighting the question of why we are not taking advice from our European neighbours. Similar lifestyles mean we are totally comparable, yet some of there infrastructure is so much more advanced.

Once systems are being mass produced and the CHP infrastructure is in place the financial savings are potentially huge. Even if the smallest CHP systems are used (which many consider to be one of the least efficient CHP variants), units will have paid for themselves and be producing a reasonable saving within 4 years:

The potential effects this project can have on sustainable development
All CHP systems have the potential to dramatically effect heat and power generation as we know it, the main obstacle is moving away from small pockets of ingenious solutions, and towards organisations working together to roll out the best solution to the whole nation. If the WhisperGen product does reach its potential (starting in early 2009), CHP systems should begin becoming the ‘norm’ and we should also quickly begin to see the positive effects of sustainable fuel usage.

Unfortunately as the alternatives described earlier highlight there are better technologies available. The main problem that all CHP units share is with them all using non-renewable fuels, by doubling efficiency we double the supply, however that only buys time and doesn’t move us away from our dependence on fuels such as coal and gas. If these technologies are to be put in place we need to use this time effectively by investing in products which move us towards fully sustainable power generation.

Leading some to ask whether we should upgrade? The upgrade would cost millions as well as the disruption and pollution caused in manufacturing, transporting and installing the units. We have the intelligence, technology and investment potential to act quickly and produce an advanced power network utilising renewable fuels rather than just trying to catch up with others.