ec-users

Questions

Page history last edited by Skander Spies 1 mo ago

How should I cool my electronics in the attic?
- Honestly, don't put them in the attic, put them under your floorboards- you are either drilling holes in your ceiling or your floor, put them down low and start off right.
Is Solar-thermal driven refrigeration possible, practical?
- Well, the short answer is yes, it's possible- it's called Absorption Chilling (you will find links to adsorption chillers too, which are pretty much the same, but operate with different refrigerants (usually lithium bromide, rather than standard ammonia or HCFCs) and at different temperatures) It may be practical in a small number of applications such as large scale district cooling (think college campuses in Southern California) where you have a large constant heat source (like a fuel cell or CHP generator). There is also this interesting article which essentially discusses desiccant driven comfort. This really just dehumidifying, not very much "sensible" cooling, e.g. your thermometer doesn't drop much, but the air is more comfortable because your sweat evaporates better in dry air.

How much energy is lost when generating electricity from fossil fuels, wind, PV, etc? How about in transmission?
- At Glumac, we usually figure top of the line gas turbine generators convert natural gas to electricity at about 41%. With a CHP, you can recover up to 60-65% of the chemical energy available either as heat or power. Similarly we estimate approximately 10% transmission loss.
How much energy does driving consume?
What's Caltrain's gas mileage? (Caltrain runs along the San Francisco peninsula)
How much more efficient is Natural Gas Heat?
- Should we use ground source Heat Pumps instead?
What's the spot price of electricity during various peak times, during the 2001 manipulation/crisis, etc? i.e. when does PG&E start making money by paying you top tier rates for the kWs coming off your PV Panels?

Is there a "Ski Bus" from the SF Bay Area to Tahoe?
- Yes, see http://www.bayareaskibus.com/
Craigslist rideshare can be a a great resource for carpooling when you don't know people who need to go where you want to go.

What is the average use for residences that are for ~2,500 sq. ft. local homes with all electric systems?
- In the Pacific Northwest for homes with electric resistance heat and natural gas hot water, we generally see averages around 16.2 kWh/s.f.-yr (40500kWh for 2500 s.f.) and for homes with natural gas space heating and water heating, 9.1kWh/s.f.-yr.
  - 22MWh/year seems like a lot for all-gas
  - Other sources suggest 1000 kWh/mo for the average house (12MWh/year) ... is 2500 sq ft that big?