Technology Heating


Why CHP makes sense


The UK’s national electricity generation and transmission infrastructure is running out of both time and money. But, as David Shaw writes, alternative power sources may offer a solution


T


he electricity regulator Ofgem has already announced that there is “rea- sonable doubt” about


the ability of


our current power infrastructure to meet increasing demand for electricity in the future. Some energy suppliers have already predicted rolling blackouts across the UK from as early as 2013 as some of the older fossil-fuel and nuclear power stations are de-commissioned. As part of the Government’s energy strat- egy, unveiled last December, Energy Minister Charles Hendry admitted it would cost £130B to make our energy supplies more secure and sustainable. That cost will have to be passed on to consumers, who are already facing a sharp rise in fuel bills this winter with pres- sure on wholesale energy prices created by the Japanese nuclear disaster and political instabil- ity in the Middle East.


According to the Minister, £100B will be spent on creating a “sustainable” power gener- ation system to meet our pledge to cut carbon emissions by 80% by 2030. The remaining £30B will go towards rebuilding and upgrad- ing existing transmission infrastructure by 2020. Ultimately, the Government would like to de-carbonise the National Grid and convert buildings to all-electric systems powered by renewable and nuclear generated electricity.


32 | Sustainable Business | June 2011 Intensive


In fact, electricity is actually getting more carbon intensive. DECC has increased – by a significant 30% – the carbon emissions factor used to calculate the environmental impact of electricity generated by large power stations and distributed via the Grid.


Therefore, any technology that generates electricity ‘off-grid’ looks even more attractive both from a financial and carbon saving per- spective. This is why we are seeing more inter- est in alternative power sources like combined heat and power (CHP). There is also growing interest in ‘marrying’ more technologies to reduce carbon intensity. For example, electric- ity generated by on-site CHP can be used to power electric heat pumps – so increasing the already significant energy and carbon emis- sions benefits of each technology. Aside from the carbon intensity, centrally generated electricity is only about 35% effi- cient. A large part of the useful energy is thrown away in the waste heat rejected via a power station’s cooling towers and still more is lost during the process of transmitting the electricity from the station to the point of


This is a commendable strategy, but it is enor- mously expensive and very long-term.


use. If the building receiving the power is also inefficient, then you are throwing away even more power.


It is clear, therefore, that we need a mixture of solutions to improve energy security in the UK. We will continue to depend on significant amounts of centrally generated electricity, but we can no longer rely on the Grid to provide everything we need.


We also have to move more quickly and


more cost-effectively than the process of upgrading the Grid allows. The first new nuclear power


stations will not come on


stream until 2018 at the earliest – possibly later now that the Japanese reactor disaster has trig- gered a complete review of safety procedures throughout the industry. Eight new nuclear sites have now been approved in the UK, but experts predict we will need double that number to plug our energy shortage by 2030. We need solutions that are more affordable and can be delivered in a much shorter time period. Microgeneration that takes the pres- sure off the grid and produces electricity in a more efficient, low-carbon way is the most realistic and reliable approach. CHP has the added benefit of providing useful heat as a by-product of the generation process exactly where it is needed.


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