D
CHP
- Thread starter HARALIAN
- Start date
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Wana bet, she can talk in her sleep, NO is her favorite word. 
B
BigBurner
How about harnessing some of the energy our vehicles create with their hydronic cooling systems.
Say have a thermal store in the boot.(vented preferably)
Could be 150 litres as we don't want to add too much weight.
The engine heats this up and when we arrive home, we drive up to a docking station which transfers the energy to the home. Could be pre -heat too a combi or thermal transfer too another cylinder. A small heat pump might be beneficial too in order to suck all the remaining lower grade heat from the store and the engine block as well before it escapes too the surrounding ambient.
Good thinking. Oil holds more energy than water, so a tank of oil would be better. Better still is crystals which hold an amazing amount of heat. These are used to store engine heat and give it out to defrost windscreens in Scandinavia. However as we are all going over to electric cars soon, there will be little waste heat created to transfer into homes.
A Prius car plugs into a house to power it.
Many have thought this a great way of using dispersed power generation using efficient on-board Stirling engines to create power and charge batteries. As well as CHP gas units.
http://jalopnik.com/5118297/tech+savvy-prius-owner-uses-hybrid-to-power-house-during-snow-storm
"When an ice storm knocked out power to much of New England, one Toyota Prius owner reached for his inverter and powered some of his home with the happy little hybrid. Smug FTW? Yes.
John Sweeney, of Harvard, Massachusetts, was among the many residents of Eastern Mass without power after a big ice storm hit on December 12th. Sweeney, an electrical engineer, saw his Prius as the answer. Using an inverter, he converted the DC power coming out of the car into AC power for his house. Though he couldn't run his entire house one his one car, they were able to get approximately 17 Kilowatt hours of energy. This was enough to power his refrigerator/freezer, television, lights, wood stove fan and accessories for a few days. Although anyone can use a regular DC power supply, like the battery found in a non-Hybrid car, but a hybrid is ideal.
First, the Prius carries a much larger batter pack than a regular car, allowing someone to power more appliances for longer than the conventional AC Delco found in most cars. Second, unlike some backup battery systems found in homes, the Prius, like other cars, can recharge its batteries with its normal internal combustion engine. And here's the best part — because the Prius automatically turns itself on when the batteries drain to a certain level, Sweeney left the car running and it automatically turned over when it needed to recharge — about once every 30 minutes. If you were trying to do what Sweeney did with a non-hybrid, you'd find yourself spending a lot more time outside in the cold. The efficiency of the auto-on feature meant Sweeney only used around five gallons of gas. As with any time you're trying to use your vehicle as a generator, you'll probably want to use a well-ventilated area.
If any of Sweeney's neighbors thought he was smug about his car choice before the storm they must have really hated him when he turned on the television and lights while they huddled for warmth on the hood of their Tahoe. "
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B
BigBurner
Powergen where into this around 2004. They imported the Whispergen from NZ. After initial reports of unreliability with many being removed it all went very quiet. Reports were that 80,000 units had been ordered. I don't think more than a few hundred were ever installed - the rollout date has been one year away for the past 5 years.
The Baxi unit is I assume based on work done by defunct British Gas subsidiary Microgen. The Microgen unit promised super reliability having a free wheeling piston (one moving part) in the Stirling engine to generate electricity. Coils in the piston and cylinder. Designed by a specialist US company.
One major problem with MicroCHP is that it only really works well in
large houses requiring high heat loads. They are not so efficient on short run cycles. The more you insulate your house and lower the
heat requirement, as the new insulation levels require, the less the CHP boiler generates as they only generate electricity (1.1 kW) over the heating load.
However this can be got around is using thermal storage and having the microCHP unit run for long burns. But, the advantage of microCHP is that the peaks of electricity usage coincide with gas usage, so gas usage of microCHP drops the electricity demand peaks. Thermal storage will mean running the microCHP unit maybe not at peak times. But having the as combis with thermal storage pre-heat would put them back on peak time usage again.
microCHP is ideal if they are subsidised in new estate developments as less electrical infrastructure needs to be run in. The microCHP copes with peaks. The power companies can subsidise the installations. It also gives dispersed power generation, so less power stations needed. Millions of homes are needed and are planned. If these homes are all fitted with microCHP the country will benefit, as well as the householder too.
However, the picture is not conclusive. A report by Advantica the research and development department of Centrica state that microCHP could probably mitigate 0.45kW of electrical load per household for eight hours a day across the winter heating period. Looks good. On an estate with say 200 homes that's around 350A. When the electrical supply for those 200 homes will be capable of circa 20000A then the gains from electrical infrastructure changes are zero because a reduction of that level has no real impact on the overall design. Scale it up to a small eco town of 10,000 homes and it makes a difference of a few 10's of amps at 132kV, insignificant and making no real difference to the design of the equipment.
The mixed conclusions that a number of studies are coming to is that CHP can work with a heating or cooling demand in a single installation of around the 250kW level but below that the picture is far from conclusive.
If MicroCHP had clear benefits for reducing carbon emissions or infrastructure costs then the likes of EdF and Eon would have been involved in a big way more than two years ago. They are not.
One thing is clear the enthusiasm for microCHP has dropped off. But do not discount political interference, either from corporations a or government.
The Baxi unit is I assume based on work done by defunct British Gas subsidiary Microgen. The Microgen unit promised super reliability having a free wheeling piston (one moving part) in the Stirling engine to generate electricity. Coils in the piston and cylinder. Designed by a specialist US company.
One major problem with MicroCHP is that it only really works well in
large houses requiring high heat loads. They are not so efficient on short run cycles. The more you insulate your house and lower the
heat requirement, as the new insulation levels require, the less the CHP boiler generates as they only generate electricity (1.1 kW) over the heating load.
However this can be got around is using thermal storage and having the microCHP unit run for long burns. But, the advantage of microCHP is that the peaks of electricity usage coincide with gas usage, so gas usage of microCHP drops the electricity demand peaks. Thermal storage will mean running the microCHP unit maybe not at peak times. But having the as combis with thermal storage pre-heat would put them back on peak time usage again.
microCHP is ideal if they are subsidised in new estate developments as less electrical infrastructure needs to be run in. The microCHP copes with peaks. The power companies can subsidise the installations. It also gives dispersed power generation, so less power stations needed. Millions of homes are needed and are planned. If these homes are all fitted with microCHP the country will benefit, as well as the householder too.
However, the picture is not conclusive. A report by Advantica the research and development department of Centrica state that microCHP could probably mitigate 0.45kW of electrical load per household for eight hours a day across the winter heating period. Looks good. On an estate with say 200 homes that's around 350A. When the electrical supply for those 200 homes will be capable of circa 20000A then the gains from electrical infrastructure changes are zero because a reduction of that level has no real impact on the overall design. Scale it up to a small eco town of 10,000 homes and it makes a difference of a few 10's of amps at 132kV, insignificant and making no real difference to the design of the equipment.
The mixed conclusions that a number of studies are coming to is that CHP can work with a heating or cooling demand in a single installation of around the 250kW level but below that the picture is far from conclusive.
If MicroCHP had clear benefits for reducing carbon emissions or infrastructure costs then the likes of EdF and Eon would have been involved in a big way more than two years ago. They are not.
One thing is clear the enthusiasm for microCHP has dropped off. But do not discount political interference, either from corporations a or government.
Its not surprising that companies involved in generation and resale of electricity will not have a serious interest in promoting something that reduces demand for their products.
The main difficulty with the one design of CHP which we have heard about is the very limited electricity generation of about 1 kW.
The reality is that most households have a day time occupied consumption of well over 1 kW to cover freezer, computer, central heating, some intermittent lighting and the radio/TV and some intermittent loads like the washing machine and dishwasher.
Come the evening and that increases with lighting and more heavy use of TV and computers and many households are using 2-3 kW much of the time.
The CHP design needs to be able to cope with variable electrical demands of ideally up to about 3-5 kW. It would be possible to maintain a constant electrical load by converting the surplus electrical energy to heat.
The whole benefit of CHP is that during the heating season the waste heat from electrical generation is used beneficially in the home whereas at power stations it has to be disposed of to atmosphere.
Tony
B
BigBurner
Average loads are well under 1.1kW you are on about peak loads. Any surplus energy gets fed into the grid
The whole benefit of CHP is to have dispersed power generation, with some economic spin offs to the home owner.
It is not to generate all a home's electrical energy. One model would not work in a power cut.
If the CHP cannot work during a power cut then a potential advantage is lost.
However, to start up with no electricity would need a standby battery and inverter.
Many homes would see generation during a power cut as very advantageous. The reality is that power cuts are very rare in towns and cities.
My friends in a Midlands village had no power for about 6-7 days after the gales during 1994 (?). He rigged up a small petrol gen to run his gas boiler but the freezer had it but he could claim for all the food on the insurance. He ate all the best food though.
Tony
However, to start up with no electricity would need a standby battery and inverter.
Many homes would see generation during a power cut as very advantageous. The reality is that power cuts are very rare in towns and cities.
My friends in a Midlands village had no power for about 6-7 days after the gales during 1994 (?). He rigged up a small petrol gen to run his gas boiler but the freezer had it but he could claim for all the food on the insurance. He ate all the best food though.
Tony
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My friends in a Midlands village had no power for about 6-7 days after the gales during 1994 (?).
YOU have FRIENDS?
Ahhh, I see you had friends in 1994.....
YOU have FRIENDS?
Ahhh, I see you had friends in 1994.....
D
Deleted member 105431
Is there a particular make of chp you would recommend Bigburner?
Ask jeeves then
having worked with real CHP's for years, they mostly seem to favour american large 4 stroke engines, and dont last long on bio gas.
but can do 200kw/hr and are favoured by water companies.
however, for a small domestic setup it appears the sterling engine design is being favoured.
any input on that subject zimmers/ajs plumbing/watersystems/dr drivel/gordenspants/any other reinvention you have come up with recently?
AKA big burner, who used to work for nuway hence the non de plume
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