I HAVE been talking to David Shaw, managing director of Baxi Senertec UK, which makes the Dachs CHP unit.

For those who do not know, a combined heat and power unit is an engine which runs on gas, LPG or diesel. The engine generates electricity and in the process of generating electricity it gives off heat.

In a car engine this heat would be sent to atmosphere. However, the heat from a CHP unit is used to heat hot water. Shaw says the CHP unit is ideal for hotels, schools, hospitals or care homes and anywhere else that uses electricity and also needs lashings of hot water. The economies come not from generating the electricity on its own but from using the water as well.

Any spare electricity generated can be sent to the grid. But in the UK the utility companies do not have to buy any spare electricity. It could be a CHP owner would export spare electricity to the grid and receive nothing for it then be charged 12p a therm when he had to import it. Not very fair, because the longer the CHP unit runs, the more economic it becomes. So it is most economical if it runs all the time.

The Germans, on the other hand, operate a very different system and have recently beefed it up. The utility companies have to take any spare electricity generated by CHP and they pay the provider between 11.6 Euro-cents and 13 cents per kilowatt. Although the scheme is administered by the utilities, government pays the bill.

But now the German government has extended the tariff so that it pays 5.11 cents per kilowatt when the CHP unit is generating electricity for its owner's use. Perhaps this is why there are 18,000 Dachs CHP units in Germany and not anything like as many in the UK.

It certainly makes sense because the mini CHP units, used properly, are far more efficient than a gas-fired power station because the waste heat there is sent straight to atmosphere.

The UK government is seemingly desperate to cut emissions. Changing the set up from the allowances system (which I am told is virtually worthless as those who attempt to get any money are usually put off by the bureaucracy) would be an easy way. It would reward small businesses for generating their own electricity. And the German government has guaranteed the tariff system until 2016.

UK government is a good few years behind with its next generation of power stations. It could do with a bit of a hand. But it would have to think out of the box. According to Shaw, his CHP units are fitted with a modem, which is used when necessary to monitor the system - internally or externally.

But it would be possible to send out a signal to switch on or off every unit so that, if there were a power failure of any size, then these local generators could be used to replace some of the electricity. For me, this system makes sense. For the Germans, the more electricity generated by CHP owners the fewer power stations they have to build. For the owners, the more the CHP unit is used the more money received from government.

Better than some of our schools which have installed biomass boilers so that they can be seen as green and they sit there idle.

I think changing the funding of CHP from an upfront allawance to feed-in-tariff is such a good idea that I have posted a petition on the PM's website. Anyone who wants to sign it should go to: http://petitions.pm.gov.uk/feed-in-tariff/

Paul Braithwaite, editor