4 ms·
Is it though? It might be cheaper in many area's but this source [1] says that the grid transmission loss is only 5%. Am I missing something that makes it a mo
by tacLog 5y ago
Is it though? It might be cheaper in many area's but this source [1] says that the grid transmission loss is only 5%.
Am I missing something that makes it a more substantial difference?
Not to mention that piping all that natural gas out to each home has to result in a certain amount of leakage and energy cost in just the pumping itself.
[1] https://www.eia.gov/tools/faqs/faq.php?id=105&t=3#:~:text=The%20U.S.%20Energy%20Information%20Administration,in%20the%20State%20Electricity%20Profiles https://www.eia.gov/tools/faqs/faq.php?id=105&t=3#:~:text=Th....
- simlan 5y agoGas to electricity efficiency is low so you loose more then half the energy when producing electricity from gas. Using a 90 percent efficiency furnace to heat water directly with gas is the better solution. Assuming your electricity comes from gas plants.
- ZeroGravitas 5y agoHeat pumps can have COPs above one so if your entire electrical grid was gas fired then youd need a COP of around 3 to break even which is doable. The grid is getting greener which means you win by even more if you electrify everything.
- Gibbon1 5y agoThat's what I've seen. Heat pump water heaters cost about the same to run as gas units. And yes the advantage is they don't fundamentally use natural gas so they are 'green' as the grid they are tied to is.
- scotty79 5y agoHowever if you heat with heat pump you are getting more than 3 times more heat than electrical energy you used. So despite getting only 0.5 energy by turning gas into electriciy you are getting 3*0.5 = 1.5 of heating and you could go in reverse and get the cooling when you need it. If you have a gas line to your home the most efficient way of heating would be to have co-generation gas turbine than makes heat and electricity and then use the electricity produced to power heat pump.
- MertsA 5y agoYes, even the most efficient natural gas plants aren't going to come close to the efficiency of a modern condensing gas water heater. For the water heater it's just a matter of a single heat exchange process from the exhaust to the water. For a combined cycle power plant you're dealing with a gas turbine and boiling water to run additional steam turbines but in the end converting heat into mechanical energy is not tremendously efficient. Figure on the order of 60% efficient for the best natural gas power plants vs. 95% efficient for a condensing gas water heater. Not to mention the drastic reduction in expensive electrical infrastructure, the power plant, etc.
- tacLog 5y agoThank you, I was not aware that natural gas generation was so inefficient. I wonder how from a pure greenhouse gasses perspective, the numbers stack up. I know that leaked methane is much worse than CO2. 28x according to [1] This source [2] says that the grid looses: 2% - 5% of gas between provider and consumer. Even assuming that your grid is 90% just gas plants stil. 30% loss at the power plant, 5% loss from electrical grid. So for every unit of water heated you are wasting 35% of the energy. Vs say 2% loss in the natural gas grid. but that 2% is 28x worse than burned CO2. Am I completely wrong in saying that from a pure this hurts the planet more electric based water heaters often probably still win? [1] https://www.epa.gov/ghgemissions/understanding-global-warming-potentials https://www.epa.gov/ghgemissions/understanding-global-warmin... [2] https://pubs.naruc.org/pub/FA86BB52-AE3F-D8AC-B295-801BD6DC6435 https://pubs.naruc.org/pub/FA86BB52-AE3F-D8AC-B295-801BD6DC6...