<![CDATA[Grist - Comment Feed for Two homeowners, one monster, and a cutting-edge power source]]> Grist Comment Feed en Comment #1 by BCC http://www.grist.org/article/2009-05-05-homeowners-power-source/ Fri, 15 May 2009 13:41:27 -0700 http://www.grist.org/article/2009-05-05-homeowners-power-source/1 I had to replace an old gas boiler in my house this past January (we just moved in, and didn't trust our old monster, either).  In my case the incremental cost was more than $3000, and my capital budget is a bit constrained this year, so we went with a FreeWatt Ready system.  This is basically just the gas boiler and hot water tank, but I can now easily add the generator when I have the dough for it.  The boiler itself is very quiet and efficient.


The economics of a freeWatt didn't blow me away, but it's not a bad investment either.  I do recommend that anyone facing a boiler/furnace replacement take a look.

 


]]> I had to replace an old gas boiler in my house this past January (we just moved in, and didn't trust our old monster, either).  In my case the incremental cost was more than $3000, and my capital budget is a bit constrained this year, so we went with a FreeWatt Ready system.  This is basically just the gas boiler and hot water tank, but I can now easily add the generator when I have the dough for it.  The boiler itself is very quiet and efficient.


The economics of a freeWatt didn't blow me away, but it's not a bad investment either.  I do recommend that anyone facing a boiler/furnace replacement take a look.

 


]]> Comment #2 by thollandpe http://www.grist.org/article/2009-05-05-homeowners-power-source/ Sat, 16 May 2009 05:38:52 -0700 http://www.grist.org/article/2009-05-05-homeowners-power-source/2 This article is superbly written! Photos are good too, great Grist. 

My guess is that your investment will be even better than you think.  My boiler replacement project paid back in four years because the actual, real-world efficiency of the old unit (propane-fired w/ indirect domestic hot water) was way lower than I estimated. 

Best of luck, and please keep us updated.  Oh, and can somebody track the return of investments like this against something more conventionsal, like a 401k? 

]]> This article is superbly written! Photos are good too, great Grist. 

My guess is that your investment will be even better than you think.  My boiler replacement project paid back in four years because the actual, real-world efficiency of the old unit (propane-fired w/ indirect domestic hot water) was way lower than I estimated. 

Best of luck, and please keep us updated.  Oh, and can somebody track the return of investments like this against something more conventionsal, like a 401k? 

]]> Comment #3 by Biodiversivist http://www.grist.org/article/2009-05-05-homeowners-power-source/ Sat, 16 May 2009 15:06:54 -0700 http://www.grist.org/article/2009-05-05-homeowners-power-source/3 The NYT GreenInc blog recently  ran a similar story:

http://greeninc.blogs.nytimes.com/2009/04/29/a-winters-tale-my-first-season-with-micro-combined-heat-and-power/#more-7243

From this article: http://www.aboutmyplanet.com/environment/combined-heat-and-power-as-small-as-your-dishwasher/

"…In Britain, where the systems look like dishwashers and sit under kitchen counters, 80,000 systems made by a New Zealand company are on order…."

By installing one of the above in your insulated envelope instead of a cellar, 100% of the waste heat from the generator motor goes toward heating your home, just as the waste heat from your refrigerator does. By turning on the above generator during the day you would accomplish the following: burn natural gas, spin your electric meter backwards (assuming you are not using all of the power it makes) and heat your home with the motor's waste heat.

In a factory you already have some machine doing work that is generating waste heat. Cogeneration is where you capture that waste heat and use it to heat something or possibly to make electricity.

In a house, you don't have a machine generating waste heat to capture. This system essentially adds a machine (the generator) you didn't need in the first place so you can capture its waste heat, which is not quite the same.

In a nutshell, by paying an extra $4-5K to add to this system a generator with heat exchanger you will increase your natural gas bill to lower your electric bill. The electricity is not being generated by waste heat. The electrical energy was converted from energy stored in natural gas, losing about 20% of that energy in the process. By capturing the waste heat from the generator motor to heat your home you are only wasting 20% of the energy stored in the gas in stead of 80% if you just ran the generator without capturing the motor waste heat.

The money saved or lost depends on the price of natural gas and electricity. In theory, your total GHG emissions (from your home and the power station) may have increased or decreased, depending on your source of electricity: hydro, nuclear, wind, solar, coal, or natural gas. This is in theory only because in reality, the electric power station did not notice your contribution and did not decrease fuel burned to compensate for it. If this idea were scaleable into the tens of thousands you would actually cause the power company to use less fuel.

It is a fact that you have reduced emissions and your energy use by about 30-35% just by installing the new boiler system. The addition of a generator to this heating system did not increase its heating efficiency. It is also a fact that adding this generator as part of the new heating system has increased the GHG emissions emanating from your home and increased your natural gas bill over what it would have been without the generator.

The generator is reducing total energy consumption and emissions very little if at all but is saving money on winter energy use because of the price difference between natural gas and electricity. You can only spin your electric meter backward by burning more natural gas than is needed to heat your home.

If this system is also designed to start with a battery in the event of a power outage, it will also provide a small amount of emergency power and keep your house warm in a power outage, which is a selling point. If it does not have a battery backup to start the generator motor, then it won't have that selling point.

If you looked inside that box you should find an internal combustion reciprocating engine with a radiator like on a car, turning a generator motor. It has hundreds of oscillating and rotating parts all requiring lubrication, all wearing out. Poking out of that box you should find a natural gas line, an exhaust pipe, electrical cables, and two pipes attached to the radiator.

It can provide enough electricity to run a typical toaster oven. It only runs when your house calls for heat. If it ran 12 hours a day for five months (the heating season) it would generate 14.4 kWh per day. The average for an American home is 30.8. If your electrical use is the American average it would replace about 20% of your annual electrical use if you have net metering that allows you to spin your meter backwards. If not, it would replace much less because it would only run when 1200 watts of electricity is needed.

A generator also adds to the cost, maintenance, and complexity, thus decreasing reliability.

Adding up the positives and negatives of adding a generator to this system = (modest decrease in "annual" energy costs) - (higher installation, maintenance, and replacement costs).





























]]> The NYT GreenInc blog recently  ran a similar story:

http://greeninc.blogs.nytimes.com/2009/04/29/a-winters-tale-my-first-season-with-micro-combined-heat-and-power/#more-7243

From this article: http://www.aboutmyplanet.com/environment/combined-heat-and-power-as-small-as-your-dishwasher/

"…In Britain, where the systems look like dishwashers and sit under kitchen counters, 80,000 systems made by a New Zealand company are on order…."

By installing one of the above in your insulated envelope instead of a cellar, 100% of the waste heat from the generator motor goes toward heating your home, just as the waste heat from your refrigerator does. By turning on the above generator during the day you would accomplish the following: burn natural gas, spin your electric meter backwards (assuming you are not using all of the power it makes) and heat your home with the motor's waste heat.

In a factory you already have some machine doing work that is generating waste heat. Cogeneration is where you capture that waste heat and use it to heat something or possibly to make electricity.

In a house, you don't have a machine generating waste heat to capture. This system essentially adds a machine (the generator) you didn't need in the first place so you can capture its waste heat, which is not quite the same.

In a nutshell, by paying an extra $4-5K to add to this system a generator with heat exchanger you will increase your natural gas bill to lower your electric bill. The electricity is not being generated by waste heat. The electrical energy was converted from energy stored in natural gas, losing about 20% of that energy in the process. By capturing the waste heat from the generator motor to heat your home you are only wasting 20% of the energy stored in the gas in stead of 80% if you just ran the generator without capturing the motor waste heat.

The money saved or lost depends on the price of natural gas and electricity. In theory, your total GHG emissions (from your home and the power station) may have increased or decreased, depending on your source of electricity: hydro, nuclear, wind, solar, coal, or natural gas. This is in theory only because in reality, the electric power station did not notice your contribution and did not decrease fuel burned to compensate for it. If this idea were scaleable into the tens of thousands you would actually cause the power company to use less fuel.

It is a fact that you have reduced emissions and your energy use by about 30-35% just by installing the new boiler system. The addition of a generator to this heating system did not increase its heating efficiency. It is also a fact that adding this generator as part of the new heating system has increased the GHG emissions emanating from your home and increased your natural gas bill over what it would have been without the generator.

The generator is reducing total energy consumption and emissions very little if at all but is saving money on winter energy use because of the price difference between natural gas and electricity. You can only spin your electric meter backward by burning more natural gas than is needed to heat your home.

If this system is also designed to start with a battery in the event of a power outage, it will also provide a small amount of emergency power and keep your house warm in a power outage, which is a selling point. If it does not have a battery backup to start the generator motor, then it won't have that selling point.

If you looked inside that box you should find an internal combustion reciprocating engine with a radiator like on a car, turning a generator motor. It has hundreds of oscillating and rotating parts all requiring lubrication, all wearing out. Poking out of that box you should find a natural gas line, an exhaust pipe, electrical cables, and two pipes attached to the radiator.

It can provide enough electricity to run a typical toaster oven. It only runs when your house calls for heat. If it ran 12 hours a day for five months (the heating season) it would generate 14.4 kWh per day. The average for an American home is 30.8. If your electrical use is the American average it would replace about 20% of your annual electrical use if you have net metering that allows you to spin your meter backwards. If not, it would replace much less because it would only run when 1200 watts of electricity is needed.

A generator also adds to the cost, maintenance, and complexity, thus decreasing reliability.

Adding up the positives and negatives of adding a generator to this system = (modest decrease in "annual" energy costs) - (higher installation, maintenance, and replacement costs).





























]]> Comment #4 by splashy http://www.grist.org/article/2009-05-05-homeowners-power-source/ Sun, 17 May 2009 03:03:23 -0700 http://www.grist.org/article/2009-05-05-homeowners-power-source/4 Would this produce electricity for you when the grid is down? If so, this is a very good investment considering that disasters can happen that cause blackouts (like the ice storm we had in our area this last winter that knocked out the electricity for as long as two weeks or more for some). You would still have heat, electricity, and everything you need if you are also stocked up.


Gee, in the case of something like a very lethal pandemic you would be relatively self-sufficient if your gas supply held up.


]]> Would this produce electricity for you when the grid is down? If so, this is a very good investment considering that disasters can happen that cause blackouts (like the ice storm we had in our area this last winter that knocked out the electricity for as long as two weeks or more for some). You would still have heat, electricity, and everything you need if you are also stocked up.


Gee, in the case of something like a very lethal pandemic you would be relatively self-sufficient if your gas supply held up.


]]> Comment #5 by Clifford Wells http://www.grist.org/article/2009-05-05-homeowners-power-source/ Sun, 17 May 2009 14:41:25 -0700 http://www.grist.org/article/2009-05-05-homeowners-power-source/5 Us folks who live down south and have electric systems (some have natural gas in the cities) are rather confused.  Our largest costs are during the summer.  But I know it's a huge issue up north, where "The Monster" rules the basement for about 6 months a year.  I used to live in Connecticut in an old house that was, fittingly, equipped with a coal central heating system before being converted to a diesel oil furnace.  I know the pain.

I do know that if the grid is down, you can't force extra waste electricity into the meter box and the power lines.  That's a big issue during power outages.  Wind turbines have the same issue with having to "dump" waste power, unless you have a large battery bank and a sophisticated inverter/converter system. Who knows, the little NG reciprocating engine might have a clutch on the generator/alternator to lower or stop loads when they are not needed?  I know the little gasoline electric generators (like for construction jobs or storms) don't have to "dump" any power.

As to the question about natural gas pressure when the grid goes down, that's a good one.  Some NG compressor stations have stand-by diesel engines, not all.  Due to the properties of gases such as NG, I can imagine that adequate line pressure would be maintained for quite a while, given the high "city gate" pressures and low residential gas line pressures.  Not absolutely sure - although the survival types living in remote areas all have large propane tanks, which do work.

If a pandemic comes, though, a really slick energy system ain't gonna do very much for ya though!

]]> Us folks who live down south and have electric systems (some have natural gas in the cities) are rather confused.  Our largest costs are during the summer.  But I know it's a huge issue up north, where "The Monster" rules the basement for about 6 months a year.  I used to live in Connecticut in an old house that was, fittingly, equipped with a coal central heating system before being converted to a diesel oil furnace.  I know the pain.

I do know that if the grid is down, you can't force extra waste electricity into the meter box and the power lines.  That's a big issue during power outages.  Wind turbines have the same issue with having to "dump" waste power, unless you have a large battery bank and a sophisticated inverter/converter system. Who knows, the little NG reciprocating engine might have a clutch on the generator/alternator to lower or stop loads when they are not needed?  I know the little gasoline electric generators (like for construction jobs or storms) don't have to "dump" any power.

As to the question about natural gas pressure when the grid goes down, that's a good one.  Some NG compressor stations have stand-by diesel engines, not all.  Due to the properties of gases such as NG, I can imagine that adequate line pressure would be maintained for quite a while, given the high "city gate" pressures and low residential gas line pressures.  Not absolutely sure - although the survival types living in remote areas all have large propane tanks, which do work.

If a pandemic comes, though, a really slick energy system ain't gonna do very much for ya though!

]]> Comment #6 by amazingdrx http://www.grist.org/article/2009-05-05-homeowners-power-source/ Mon, 18 May 2009 00:34:57 -0700 http://www.grist.org/article/2009-05-05-homeowners-power-source/6 A ground source heat pump system that runs on off peak power and a battery system to run low power devices onpeak, with a few solar panels, would really beat the payback period of this system.  then as more solar panels are added it would eventually become fossil fuel free.

The cogeneration system will rely on fuel, and fuel always follows a shortage price curve that tops  inflation.  The heat pump/solar alternative makes free fuel less heating permanent after the payback period.  Fighting energy cost inflation and GHG.

Solar cogeneration would really boost the efficiency of the wgole project, harvest the geat as well as electricty from the solar panels. 

http://amazngdrx.blogharbor.com/blog

 

]]> A ground source heat pump system that runs on off peak power and a battery system to run low power devices onpeak, with a few solar panels, would really beat the payback period of this system.  then as more solar panels are added it would eventually become fossil fuel free.

The cogeneration system will rely on fuel, and fuel always follows a shortage price curve that tops  inflation.  The heat pump/solar alternative makes free fuel less heating permanent after the payback period.  Fighting energy cost inflation and GHG.

Solar cogeneration would really boost the efficiency of the wgole project, harvest the geat as well as electricty from the solar panels. 

http://amazngdrx.blogharbor.com/blog

 

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