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Honda and Climate Energy Begin Retail Sales of freewatt Micro-CHP Home Heating and Power System

The freewatt system. Click to enlarge.

American Honda Motor Co., Inc. and Climate Energy, LLC have begun retail sales of freewatt, their collaborative Micro-sized Combined Heat and Power (Micro-CHP) cogeneration system for homes.

The freewatt Micro-CHP system consists of an MCHP cogeneration unit developed by Honda paired with a furnace or boiler produced by Climate Energy. The ultra-quiet MCHP unit—based on Honda’s GE160EV natural gas engine—produces 3.26 kW of heat and 1.2 kW of electric power.

In relation to energy costs, Climate Energy test data has shown that when the freewatt Micro-CHP system replaces a typical 80% efficiency home heating system, homeowners can realize an average of 30% in energy cost savings.

The electric power produced displaces electricity that consumers would otherwise purchase from the local electric utility, saving $500 to $1000 per year on their electric bill. An additional financial savings benefit of utilizing the freewatt system is realized through the process of net metering. In states where legislated, net metering allows homeowners to sell unused electric power back to the power grid in their community, providing additional savings.

The system produces 30% less carbon dioxide emissions than a conventional heating system with electricity provided from the grid, according to Honda.

Initial sales of the heat and power units will be targeted at customers living in the Northeastern United States in conjunction with select local utility providers. The geo-targeting is due to the cold climate and high heating demand in the region which allows the system to provide the greatest benefit. The freewatt Micro-CHP systems will only be available through certified, trained, and authorized Climate Energy installation professionals.

Climate Energy and Honda plan to gradually expand production and sales of the freewatt Micro-CHP system and plan to introduce the system to other cold weather climates in the US in the future. The units will be assembled domestically in the United States with components supplied by both companies. Currently, a similar version of an MCHP system is retailed in Japan, with more than 45,000 units sold to date since its introduction in 2003.



i want this in germany


How much is this though? I couldnt find it anywhere.


I understand it generates electricity in a co-gen mode. Can you run it just for the electricity, and if so -- how much nat'l gas is needed to generate 1 kWh? Based on natural gas prices, it might be cost effective to generate 100% of your net-metered electricity... and if your local utility is using lots of coal and oil, it might even have an ecological benefit!

Mark A

How is the excess electricity reintroduced back into the power grid? Would seem to be a complicated effort on just a heater system to integrate. On some wind generators and such, there is a second meter which runs backwards for power going into the grid, and a regular meter measuring what is taken from the grid. Then a credit is given. Dont know if that works everywhere. But this seems like an excellent idea. I just want to know more about how it works.


possible here:

for mid-sized companies and official buildings: (see references)


Stormy, it looks like the unit is a bit less than 25% efficient, so you'd need about 14k BTU per kWh. A thousand cubic feet (mcf) contains roughly a million BTU and could thus generate about 70 kWh. Natural gas costs around $7 wholesale today, figure twice that for home delivery. So:

($14/mcf) / (70 kWh/mcf) = $0.20/kWh

20 cents is pretty pricey for residential electricity. I pay 8 cents but rates vary. Peak pricing can be higher for people with TOU rates, but I'm not aware of any net metering schemes that adjust for TOU. It's also not clear if electricity produced from fossil fuels even qualifies for net metering.

Cogen works great if you need the heat, otherwise you're usually better off with the grid.


As strange as this may sound, in some cases it is actually more efficient to have a condensing combination gas boiler (98% efficient), supplemented with grid electricity, than to have a CHP unit.


I think that in places where winters are not very cold,
a heatpump is a much better way to heat the home.

Max Reid

Nat-gas cannot compete with Coal in generating electricity. Even for heat, its more efficient to use portable electric heaters in bedrooms during the night and reducing the thermostat of centralized heating system.

Now with nat-gas in North America hitting the peak, you can expect its price to go up even higher. May be Nat-gas can be used in vehicless, since its cheaper than Oil.


I too want to know the cost!

Can you mate this system with a geothermal heat pump to increase efficiency? I'm in a cold climate and am interested in this technology.
To use this you need an inverter to control the electric outut and "net-meter" with the electric utility. Can this inverter handle multiple inputs? IE I want to someday add PV's, can I just plug and play the PV's into the inverter I would need for this and have it handle multiple electric inputs?

While we're on the topic of home energy use, does anyone know anything about combining a solar water heaater with an on demand water heater? Can I use my existing standard water heater as the holding tank and thereby keep it as a backup?


Some types of solar water heating systems have their own storage tank that feeds into the traditional hot water tank so that the water is pre-heated instead of ice cold when it enters the main tank. That way, even if there's not enough solar energy to fully heat the water it can still be heated by a gas or electric heater to get it up to a high enough temperature.


Isn't that how all solar water heaters function? I want to keep my regular heater, but only as a storage tank/backup, using solar as a preheater and a new on demand heater past the tank. Is this feasable? Prohibitively expensinve?

Which is a bigger improvement if I just do one: a solar preheater to the regular tank, or replacing the tank with an on demand system?


Where to begin...not all solar water heaters are preheaters. You can buy solar water heaters from Rheem and others that have a copper coil inside where the solar hot water circulates, thus heating the mains water in the tank. Some people like this because there is only one heater, saving space. There are heat exchangers that go outside a conventional water heater. It goes on and on...just search the web for information and you will see the different types.


Info on solar hot water preheating can be found on the "green home congress" of web sites:


More info at


Obviously the price is a bit of a secret.

However, this unit seems a bit on the small side. 3.26 KW might heat a well insulated apartment, but not much more. That means this can't be used as a replacement boiler but needs to be an additional boiler. However, it still looks the size of a normal boiler.

These products might be a more useful size:

hampden wireless

Systems like this have sold for around $10,000 to $14,000. They will come down in price. These systems only make sense if you need the heat, you would not run it just for the electricty.

I have thought about the same concent running on bio-diesel, I wish someone would make that.

Rick McBane

I don't know the specifics of this particular system from Honda, but an inverter may not be needed. Any Alternatng Current (AC) *motor* can be made to "generate" electricity which will back-flow into the feeder circuit (and OUT of the household IF the current generated exceeds the current demands within the dwelling).
A certain amount of electrical power is required spin a motor operating without a load (no fan, no pump, etc.) If one begins to *input* rotary power (from internal combustion engine, for example), once the input power matches the internal friction of the motor there will be practically zero current flowing into the motor. Any additional rotary power added will begin to induce a current flow OUT of the motor -- "generating" electricity instead of consuming it. This current will flow into the electrical circuits within the dwelling until the current flow meets all of the internal comsumption at the time. Any excess current beyond that demanded within the dwelling will flow into "the Grid". If you live in a state that allows "Net Metering", this excess current will turn your Power Meter backwards, hence you will be "selling" electricity to the power company at the identical per-kiloWatt Hour rate as they sell to you. If you use more power than your generate, you pay the power company for the balance. If you generate more than you use, the power company (typically quarterly) pays you.

Some jurisdictions allow power companies to sell you their electricity, but do not require them to buy any *net surplus* from customers. In that case, once you've offset your household's monthly usage, any excess electricity generated is effectively "donated" to the grid.

Inverters are only NECESSARY when DC (photovoltaic, battery, fuel cells, etc.) current is converted to AC.



I don't think you mention whether your existing heater is gas or electric. If it's gas then the benefits of a solar preheater are likely to be minimal. This is because gas heaters work on a thermostat and don't adjust so you get maximum solar benefit. If it's an off-peak electric system, it is better suited to a solar retrofit. To get the greatest benefit you need to use most hot water in the morning so that you get the full benefit of solar heating during the day.
My electric storage system died and I have replaced it with a five star instantaneous gas system. These are incredibly efficient by themselves and you can easily add solar preheating through panels and a storge tank later on.



I installed a Takagi demand-type gas water heater on our last house (worked great). It did not support pre-heated feed water. Some other flash water heaters do support pre-heating the feed water, as they can throttle the burners down as required. I would read the specs of the various on-demand water heaters available. If pre-heating is supported, they will say so.

Kit P.

'The Climate Energy Warm-air freewatt System for Massachusetts residents
has a list price of $13,500.'

But it has the word free in it.

Thomas Lanketer

This kit is hardly 'micro'. I've had my Whispergen mCHP boiler (
for 15 months and it cuts our import of grid electricity by 30% during the winter months when we need home heating. As you can see from the above link, it is a standard floor mounted boiler height and width.

I agree that a ground source heat pump is generally a better option but it depends on having access to some ground (i.e. not so easy in an apartment) and in the UK is 3x as expensive as a (£3000) Whispergen installation. It is a shame that in the UK we get a pitance for our export electricity. I got £10 fro the whole of last year but hey, I now don't have to pay income tax on that. Enough to buy 0.25L of beer to celebrate with. We now have our washing machine set on a timer to coincide with the heating cycle and soak up our electricity rather than 'waste' it on the grid.

Specs for Whispergen 8kw max heat, 1.2kw max electricity but the fuzzy logic control system can throttle output down to 5kw heat and 850w electricity.

FYI: in Germany the Senertec mCHP ( has been available for a few years now.


i know this senertec there are a lot commercials for it, but actually its not a honda and it really pricey. actually why do people compare coal with natural gas... that´s like comparing crawling on your feet with flying in a concord

Kit P.

If you are making an economic and environmental choice, comparing the alternatives would make sense. The best choice is is to let the professionals make electricity and enjoy an all electric home.


great news, for blocking global warming...

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