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Carlos S Del Castillo
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co_generation
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iuniusApr 11, 2007
Another way to think about it. All the lost efficiency in a generator eventually becomes heat. Even if your small-scale generator is less efficient than the large one, the waste heat isn't really waste because you need heat anyway. The only waste is the heat you lose in the exhaust, which presumably isn't much worse than the loss in a regular furnace.The next step of course is to use the electricity to run a heat pump. :) For those unfamiliar, under the right conditions a heat pump can put more heat into your home than the energy it consumes. Kind of like an AC running in reverse.
Closed AccountApr 11, 2007
Talking about an inefficient heater is nonsense. Inefficiency by definition is the conversion of energy into heat.
farticusApr 11, 2007
Transmitted electrical power has losses as high as 75% and that heat goes into the environment, therefore these co-generation systems are far more efficient, if you don't take into account possible pipeline losses of gas. I have no idea what "average" gas losses may be or how significant they may be compared with electrical generation and transition losses.The heat pump idea is a very good one, it would push the heating efficiency higher again, if it is heat that you need. A good option for those gloomy still days when wind and solar are not much use to you.
Closed AccountApr 11, 2007
sleazy:>My monthly electric bill is about 30$ and my monthly gas bill is about 275-300$ and I don't even live in the house yet.No wonder your electricity bill is $30. You don't live there. When you live there, it'll be much, much higher.
sizzorApr 11, 2007
This is a good start, but they're going to have to do better than this. The Freewatt only makes 11,000 Btu of heat, and the fact that is needs electricity means you can't use it as a backup generator in the event of a power outage.Hopefully the $13,000 cost will come down. What you are basically paying for is a very expensive furnace that will make electricty in the colder months. The rest of the year you'll be making payments and getting nothing in return.
cybermageApr 11, 2007
Considering where I live gas is much more expensive than electricity... why would I do this again?
iuniusApr 12, 2007
7.5% is a more realistic estimate for grid losses. Maybe you forgot the decimal point. I also have no idea how much energy is used getting gas through the pipeline.
mitbetaApr 12, 2007
Using the freewatt system allows you to get more out of the same gas that you are burning anyway. The cogeneration side of the freewatt system only makes 11,000 BTU/hr of heat, but the high efficiency furnace side can provide as much heat as is needed in the house.Grid transmission losses are on the order of a few percent, but the real inefficiency is in the power generation itself. A typical power plant is only about 40% efficient, so 60% of the fuel energy becomes heat that is wasted. Then the 40% that is left over looses a few percent while being transmitted to the home.The freewatt system uses 90% of the fuel energy to make electricity AND heat for the home.
mrshineyApr 13, 2007
allaboutdatiki said: "Wouldn't it be cool if the Gas Company gave a nice fat rebate to folks who switch from oil heat to natural gas when they install this system?"It WOULD be very nice. Instead, when the gas company came through my neighborhood last year, installing gas lines they talked to all the homeowners and told them how great gas was, cheap, etc. and suggested we order a hookup. We were offered the chance to pay about $500 for the hookup, plus however many thousands to convert heat and appliances over to gas. I wasn't the only homeowner who said "No thankyou."A lot of new construction have gas service. This is because the gas co. routinely gives big kickbacks to the construction co. if they install gas heat, etc.
speedracer247Feb 8, 2009
The energy savings comes from elimination of the large electrical transmission loses when the same process is used by utility companies.I'm looking into how effective the system would be in running ac systems in the summer, I suppose we need to buy the solar panels too.Does anyone know if the utility companies will actually pay us back when we add more power back to the system then used over the course of a year?
petkanOct 7, 2009
Here is the story:Central thermal power stations have less than 40% efficiency. The rest is waste heat.Co-generating furnace produces electricity, but is regulated by heat demand. Its "waste' is electricity, dumped to the grid (for payment).The key here is the concept of decentralized power generation - complementing the central power plants.By producing electricity we relieve the grid of demand - it can fulfill at 40 % efficiency and we also do so at peak demand hours.When we come from work and raise our temperature from say 18 to 22 deg C we start producing electricity during peak demand time.It helps the utility - to satisfy the peak demand it would have to maintain excessive equipment iddling throughout most of the day or borrow or buy peak energy. Japan has pioneered a subdivision of 25000 co-generating furnaces and their utility is very enthusiastic.Australia is also way ahead in this field. It has the potential to reduce CO2 emissions by 30 to 50%. (by central power plants producing less).
petkanOct 7, 2009
Co-generating furnaces can come very different in design:Some rely on combustion engines (Honda), some on Stirling engines (CoGen), some on thermal photovoltaics (the quietest of all).They use numerous fuels-natural gas being the most common. Efficiency around 30% is not important, because whatever is not converted into electricity is still useful as heat. Some systems can also harness solar heat absorbing panels on the roof.Thermal differential is all needed. As water falling from high to low makes energy - heat flowing from hot to cold does too.A stirling engine fed by solar panels as hot end and your boiler as cold end can produce electricity while heating water.Solar or coal or natural gas or wood chips - no matter what the heat source is - it can still work.They cost about 3 times more than conventional furnace, but at the present "feed in tariffs" introduced with the Clean Energy Act in Canada paying you 5 times the market cost per kWh - it is the best investment.
petkanNov 23, 2009
You will be able to benefit throughout the year and generate electricity while getting hot water. Hot water is about 30% of your gas bill. The system could also be combined with other heat sources as the simplest heat absorbing panels on your roof. In fact some utilities do just that - have solar collectors and boilers with classical steam turbo-generators.