o.k. what's the deal? - shocked?

GCNRevenger · 2005-04-08 14:58:51

Transmission is a huge energy loss, not a minor one at all.

Roof-mounted arrays that would last, last as long as a regular roof would if not a little longer, would radically reduce the amount of energy needed for urban needs.

Dook · 2005-04-08 15:00:58

They are expensive, not only the solar panels ($800-$900 for a single 185 watt panel) but each home would need an inverter which alone runs about $2,000. That is one reason why I prefer large solar farms.

Dook · 2005-04-08 15:10:53

Found one reference that says line loss can be as much as 30% over long distances so I guess that is quite a lot.

Commodore · 2005-04-08 15:38:39

I had a thought. Is it possible to use large amounts of water, in say a swimming pool, to generate power like a hydroeletric plant?

Say theres a swimming pool with series of drains in the bottom. Those drains direct water trough pipes, past a series of hydroelectric generators at high pressure, and that pressure then pushes the water up through a tube that dumps the water back in the top of the pool.

BWhite · 2005-04-08 15:58:51

Transmission is a huge energy loss, not a minor one at all.
Roof-mounted arrays that would last, last as long as a regular roof would if not a little longer, would radically reduce the amount of energy needed for urban needs.

This also is my understanding of the situatioon.

We are about to re-roof this summer and I had forgotten I had once intended to look into solar shingles for the portion that slopes southwards. Thanks for the reminder.

BWhite · 2005-04-08 16:03:33

I had a thought. Is it possible to use large amounts of water, in say a swimming pool, to generate power like a hydroeletric plant?
Say theres a swimming pool with series of drains in the bottom. Those drains direct water trough pipes, past a series of hydroelectric generators at high pressure, and that pressure then pushes the water up through a tube that dumps the water back in the top of the pool.

I believe you need a rather substantial differential in heat to run an engine.

Several years ago, I started looking into an idea to add solar heating covers to the pool that holds our town's treated wastewater (i.e. water that has already been treated for release into a nearby river) with the intention of running some sort of heat pump using rather large quantities of municipal water as a heat sink.

As I recall, it was not at all easy to make electricity in this fashion. But air conditioning and heating? Very much easier.

RobS · 2005-04-08 16:08:56

Power line losses add up over long distances in spite of the high voltages. Right now power is rarely sold over distances of more than about 1000 miles.

The big problem with rooftop systems is the occasional ten days of cloudy weather; then everyone in the entire metropolitan area suddenly has to buy power from the power company. It's one thing to store power for, say, twenty-four hours; another to build systems large enough to store it efficiently for many days. Even a 24-hour storage system for a house is probably too expensive. Remember, a house usually consumes less than $1,000 of electricity per year. If the system cost $20,000 and has to be replaced every twenty years, it's a break-even situation. Add a few hundred bucks per year of maintenance and it loses money.

I am not sure how the swimming pool example is not a perpetual motion machine. . . but if you mean two swimming pools and flowing the water between them, you're talking about a very expensive system to make a little bit of power. Remember, one cubic foot of water weighs 62.4 pounds. You need about ten cubic feet falling one foot, or one cubic foot falling ten feet, to make one horsepower, which is three quarters of a kilowatt. You can't make the water "high pressure" without using electricity to pump it, which defeats your purpose. When the "head" (vertical distance falling) is low, the water flows slowly and you need a big turbine, spinning slowly, to make the power. No one makes hydroelectric power on small brooks and streams any more because it is not economic, and they involve more water or more head than your two swimming pools. In the nineteenth century there were plenty of sawmills and flour mills on small streams, but that's because (1) they were designed to work slowly on two or maybe five horsepower, and (2) that was the only power available. If you go to Sturbridge Village outside Boston, Massachusetts, you can see an early nineteenth century sawmill that is still functioning (they use it to saw boards to repair their historic houses; the village/museum is a reconstructed 1830s New England village and run the way the villages were run in that era). The sawmill operates on about ten horsepower and employs two or three men constantly. Nowadays such a sawmill would go out of business; a modern sawmill would use ten times as much power and produce ten times as much per worker.

-- RobS

Grypd · 2005-04-08 17:12:28

Our problem is that we have almost no real effective way to store power when it is not required. A power station takes a minimum of many hours to power up and often days so when a demand is needed then there are very few power sources that can quickly "come on line". The best is Hydro power which can have electrical generation coming from its turbines quickly when needed. Another benefit of hydro is that when power is not needed across the grid it is possible to use the spare capacity to reverse the turbines to pump water back up to higher lochs and when it is needed it can be activated to pump water back down at peak need.

Another more modern possible way to store "power" is to use Fuel cells to provide peak power need and to have the system reversed when we have little need for power but still have generation going. Another advantage to fuel cells is that this system can be made to work anywhere unlike Hydro which is very terrain dependant

SpaceNut · 2005-04-21 12:19:06

Well from local paper here is the start of the conflicts.

House votes for oil drilling in an Alaska wildlife refuge, setting up likely conflict with Senate

A broad energy bill that Democrats said would funnel billions of dollars to highly profitable energy companies while doing little to promote conservation or ease gasoline prices.

other parts of the bill

The bill calls for $8.1 billion in tax breaks over 10 years, most of it going to promote coal, nuclear, oil and natural gas energy industries.

SpaceNut · 2005-04-28 08:59:38

Where can I buy one?

Green Machine Drives For Ultra Fuel Savings

Granted this is only a foam model of the hybrid car called
UltraCommuter but wow if it can live up to the claims.

a clean, light, solar-electric concept car that will use 83 per cent less fuel and emit 87 per cent less greenhouse gases than a Holden Commodore.

Details of the vehicles design:

a two-seater car
driven by two electric motors, one in each rear wheel,
powered by a lithium ion battery pack.
driving range of 500 kilometres with the addition of a gas tank and a top speed of 150 kilometres an hour.
Filling the car with fuel would be as easy as parking in the sun to recharge the battery pack using the 2.5 square metres of transparent solar cells on the bonnet and back windscreen
The car would only weigh about 600 kilograms thanks to an aluminium and carbon-fibre body which was designed for its low drag aerodynamics including wheel covers to cut down wheel drag.

SpaceNut · 2020-06-28 18:31:24

another old topic to fix with pebble reactor mentioned

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#51 2005-04-08 14:58:51

Re: o.k. what's the deal? - shocked?

#52 2005-04-08 15:00:58

Re: o.k. what's the deal? - shocked?

#53 2005-04-08 15:10:53

Re: o.k. what's the deal? - shocked?

#54 2005-04-08 15:38:39

Re: o.k. what's the deal? - shocked?

#55 2005-04-08 15:58:51

Re: o.k. what's the deal? - shocked?

#56 2005-04-08 16:03:33

Re: o.k. what's the deal? - shocked?

#57 2005-04-08 16:08:56

Re: o.k. what's the deal? - shocked?

#58 2005-04-08 17:12:28

Re: o.k. what's the deal? - shocked?

#59 2005-04-21 12:19:06

Re: o.k. what's the deal? - shocked?

#60 2005-04-28 08:59:38

Re: o.k. what's the deal? - shocked?

#61 2020-06-28 18:31:24

Re: o.k. what's the deal? - shocked?

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