Ed Frugal: I think you mean:
tops out at about 5.1 kwh/hour (equals 5 kw), most I’ve ever gotten in a day is just under 40 kwh, I get a lot of 30kwh+ days in the summer. I get 800 to 900+ kwh per month in the summer months, and at least 300kwh/ month in Dec & Jan. About 7000 kwh a year.
watts or kw are units of power, the rate of energy per unit time.
watt-hour or kw-h are units of energy.
for example, a 100 watt light bulb uses power at the RATE of 100 watts, which is energy used of 100 watt-hours every hour, energy of 100 joules every hour. Or power at 0.1 kW, and energy used of 0.1kW-h every hour.
The good thing about the solar power is(and this is fairly likely)if the grid goes down you will probaly have power on.I looked at a good “Iron Edison” systemfor 15K,which would serve a lot of households(with a little disicpline very nicely(and uses the nickle- iron cells,rather then the fragile lead acid batteries)look on it as a hobby and your home"free",would you rather put $20,000 in a rusty moneypit(sitting in your driveway disintergrating)or a system that would keeps your refrigerator running and the lights on in a power outage?(solar has other good uses too-put a water coil in your parked windows up gasless auto and enjoy the supply of 120-130 degree water you could extract from it when the sun shines(who said a solar collector had to be complex?) The best energy source in the world rises in the east everyday in the northern hemisphere
People we have the solutions,We lack the will.
Companies are putting solar cells on cansumer’s roofs and selling electricity to them. They started in the Southwest, but are working into the Middle Atlantic area now too. We get almost 50 inches of rain here annually, and these companies think they can make money. If they can make a profit, home owners can too. Their equipment acquisition costs are a bit lower because they buy in bulk, but that means home owners take a little longer to pay off the equipment. Yes, state and federal tax benefits make payoff quicker, and the power company is required to buy excess electricity. But all you are doing is using the system to your advantage. Also consider that building power plants is very expensive and home electric generation plus conservation can put off building those power plants.
Tesla Corp, whose huge new L-Ion battery factory will be coming online soon will change the math when it comes to using solar power…They are already selling large Lithium storage batteries aimed at storing solar power on site instead of using the grid as a storage system…Also, the price of solar panels has collapsed compared to just a few years ago so the entire solar energy argument is in a state of flux…Backstage, LED lighting is replacing ALL existing forms of illumination greatly reducing night-time power demand…Nobody is building any new coal-fired power-plants…
The BMW energy storage experiment is using batteries from scrapped electric cars…This pilot study is using batteries from 10 or 15 Mini-E’s …
I agree that the final solution will be homes clad in solar collector cells which continuously gather power and charge large battery packs.
A typical day’s commute will use at least 1-1.5 gallons of gasoline, representing 8-12 lbs of gasoline at 15,000 BTUs per pound equalling 35-53 KWHs of electricity. That’s 1-1.5 times my daily usage in a 4 bedroom house. These are all rough figures to show the problem.
So the electricity for one normal size car will nearly double the power requirement. We’re not talking Al Gore’s house here.
For a family with 2 electric cars, solar collectors will be a must; a “smart grid” with owners feeding power back to the grid would be ideal.
Having said all that, for a retired couple who drive little this electrical load would not be a problem.
Caddyman, you made a good point. Until Tesla entered the car business, the industry of energy storage was crawling along at a snail’s pace, Lithium Ion was considered usable for watches, high-end cameras, and portable power tools, but that’s it. Tesla has already changed the landscape considerably. It’s as if the field of energy storage was suddenly shifted from first gear to fifth gear.
My guess is that we’re going to see big changes in this arena in the next decade. Especially if Tesla approaches the field in the same way it approached EVs.
for example, a 100 watt light bulb uses power at the RATE of 100 watts, which is energy used of 100 watt-hours every hour, energy of 100 joules every hour. Or power at 0.1 kW, and energy used of 0.1kW-h every hour.
100 watts is 100 joules of energy per second, not hour.
100 watt-hours is 360 kilojoules of energy.
Another common misconception is that the unit of power called the watt is an electrical unit defined by volts and amps. Actually, that definition is backwards, it is the watt that determines the volt, the unit of electrical potential called the volt is defined as the amount of potential that causes one amp of current to deliver one watt of power.
The unit of mass known as the kilogram, the unit of distance known as the meter, and the unit of time known as the second are the three basic units of the S.I. system.
All other units are derived from these three basic units.
The unit of force, the Newton, is defined as the amount of force needed to accelerate one kg of mass at a rate on one meter per second squared.
N = kg-m/sec^2
Joule = N-meter = kg m^2/sec^2
watt = joule/second= kg m^2/sec^3
If you are lifting something that weighs one Newton at a rate of one meter per second, you are delivering one watt of power to the object you are lifting.
The ampere was once a basic unit and the S.I. system used to be called the kg meter, second, ampere system, but when the physical constant of the permeability of free space became 4pi X 10^-7 Teslas-meters/ampere became exact by definition, it turned the ampere into a derived unit.
N = kg-m/sec^2
Joule = N-meter = kg m^2/sec^2
watt = joule/second= kg m^2/sec^3
The ampere was once a basic unit and the S.I. system used to be called the kg meter, second, ampere system, but when the physical constant of the permeability of free space became 4pi X 10^-7 Teslas-meters/ampere became exact by definition, it turned the ampere into a derived unit.
GREAT !..Now my head hurts. At least it’s not too early for bourbon.
Response to Bill Russell (& BLE): Yeah, what you said. I freely admit I’m not familiar with the technical aspects / proper nomenclature. What I did was write a check. The contractor installed the system.
Response to kmccune: No, when the power goes out the system stops producing. Its a failsafe system, in other words, when the power is out, the linemen cannot have solar systems feeding power back into the grid when they think they are handling dead power lines. I’ve been told it could be upgraded into such a system, but that would require significant additional expense, installation of batteries, etc. too complicated and expensive.
That’s one thing that worries me a little, if the power goes out for an extended period, my neighbors may want to plug their refrigerators into my house, thinking I have power because of the solar panels when in fact I don’t.
I live in southern california, as you probably know
I have 2 homes, and they were both built in the 1950s . . . no insulation in the walls, whatsoever
Very minimal insulation in the attic and under the roof
There are/were some incentives to add insulation and better glass at one point. But the math didn’t really work out in my favor. Not at the time, anyways
From what I understand, insulation here is a very recent development
I saw an article at the USA Today web site that discussed Li-ion batteries. Tesla will be the major manufacturer in the US when their factory comes on line, but there are others in the business. Build Your Dreams, an auto company brought to us by Warren Buffet via China, Foxconn (iPhone batteries) and LG Chem will be the major players in the near term. IRC, Foxconn is also Chinese and Lucky Goldstar is Korean.
I've looked into them in the past, but up here in NH they're really not practical. Way too much of our weather is overcast, days are too short in winter, and then there's the snow...... they don't work well covered in snow.
I’ve looked at them also. The cost is very high, but less then half the price they were just a few uears ago. Most of any incentives come from the state. NH has little or no incentives. Solar panels are being redesigned all the time. New Nano technology may make them more affordable.
If you have a good roof pitch (12/12) snow doesn’t really collect much.
As for being too far north and not enough sunny days…all depends on your house and location. Solar panels will stil product electricity on a cloudy day.
Guy I use to work retired to an Island off the coast of Maine. Completely self sufficient. No electricity on the island. Has to generate it 100%. With solar panels and 2 wind mills he can generate enough power to be completely off the grid. Has propane delivered by boat every other month. This is no small house…it’s a 4,000 sq/ft Log cabin. Also close enough to a cell tower.
Seems to me that being farther north, you’d just get more power in the summer (longer days) and less in the winter. You do need a roof side facing south or at least kinda southwest or southeast. I was told my roof side is like 5 degrees off of ideal. You cannot get any tax credits for panels on the other (north facing) side. And, yes, you do get some electricity on cloudy days. Even when its steady raining you get a little something.
That Nissan Leaf woulda been ideal for me previously. I worked night shift for over 20 years and could have charged the car up during the day with the solar panels, making for a “solar powered” car. But these days my employment situation is in flux and I have no idea what kind of shift I will be working when the dust settles, or how long my commute will be, for that matter, so I probably shouldn’t look for such a car right now.
The lead-acid storage battery has enjoyed a nice 150 year run as the favored technology for large capacity power storage…But you can see the handwriting on the wall…Its days are numbered…
The companies that mount arrays on your roof and sell power to you make sure that they can provide the average annual household needs for electricity. You are a net buyer in the winter and net seller in the summer. On average, you break even. You don’t want to sell too much power to the local utility. Around here, the cost from the utility is higher than the cost from the company that owns the arrays on your house, but the utility pays less to you for power you sell than you pay to the other company.
My system is grid tied. The other way is much more expensive and complicated. I did what I could within my budget. If my main concern were the collapsing of the grid (a la doomsday preppers) I would sell my suburban cookie cutter house and get a place out in the sticks somewhere. Of course, the way things are going, I may yet resort to that someday.
Yeah, I’ve heard of the companies that put their panels on your roof and then sell the power to you. Effectively, you’re leasing the panels, or they’re leasing space on your roof or something like that. Just like with cars, I don’t like the idea of possessing something (or having something attached to my house) that I don’t own outright. I bought my panels. I also own the s-rec’s that go with them, but that’s another story that’s complicated and off topic, except to say that I’ve only gotten about 40% of what the salesperson led me to believe they would sell for.
I think the biggest problem with buying solar electricity from someone with panels on your roof is that if you want to sell the house, they effectively have a say in who you sell to. They only sell electricity to good credit risks. They told me that they do not check credit ratings, but they know my credit rating is good, otherwise they would not offer the deal to me. This is not technically a lien, but it does behave like one in some ways.
Edit: You can sell to anyone you want, but if the buyer does not want the panels for some reason, you have to buy them to dispose of them. You have to buy the panels if your house buyer does not qualify to assume the agreement to purchase electricity. the agreement lasts for 20 years and if you are over 60, there is a good chance that neither you or your spouse will outlive the agreement. Not that you shouldn’t do it, but it is something to think seriously about.
