Solar Energy for my Home and Prius?

<div class='quotetop'>QUOTE(jimmyhua @ Jul 20 2006, 02:06 AM) [snapback]289252[/snapback]</div>

Hi Jimmy, try www.ases.org ,American Solar Energy Society, www.powerfromsun.com ,and [email protected] , the Solar Living Institute.
bernie

 

<div class='quotetop'>QUOTE(jimmyhua @ Jul 20 2006, 10:47 PM) [snapback]289758[/snapback]</div>

I'm interested too. In Utah, Utah Power has to buy back any power that you generate and don't use from Solar at the same rate they sell it too you for. You just have to buy their inverter (500 bucks or so). So in theory, your meter spins backwards during the day when you aren't home, and at night, you can pull off the grid at the same rate! Most states have laws requiring this, I have no idea what the deal in Guam is though.

 

<div class='quotetop'>QUOTE(sl7vk @ Jul 20 2006, 11:18 PM) [snapback]289783[/snapback]</div>

The best place to start is
http://homepower.com/
and subscribe to the magazine.

I have a 10kw electric PV solar system hooked to the power utility company.

and 2- 4x10 flat panel thermal collectors with a 120 gal tank.

In some states the power utility has a rebate program, in NY state the power utility wil pay $3.50/watt
so a 10kw system they will pay you $35,000.00 after it is installed and passes their inspection.
a 10kw system installed will cost $85,000.00 so the actual cost to you will be $50,000.00
I am located at Long Island, NY and have had the system working for 2.5 years.
I take readings every month and calculate the power generated.
THe power varies from summer to winter but the total yearly output for my system is 10,000kwh.
I pay about 20cents/kwh so .20x10,000=$2000.00 worth of electricity per year.
so you can see if it cost you $50,000.00 it will take you 25 years recoupe your costs.

I use about 15000kw/year so I still have a electric bill but it is reduced by about 70%.
(we are a family of 4 in a 2000 sqft ranch)

The bottom line is if you are handy and can install the stuff yourself and get a state rebate, it will be worth it.
(if you don't mind not counting your labor)

If you are going to hire a "solar installer" to install the system, it is NOT worth it.

here is a link to my install of the 10kw Pv system.
I designed my own mounting hardware because I do get hurricanes coming through here and the mounting racks they sell are only rated for 110MPH winds.
a 10kw PV solar install


Alot of people get a 5kw system which cuts the cost of the system in half but that also
cuts the power produced in half which this has a 25 year recoup cost.


The hot water solar I installed about 3 months ago. 2-4x10 solar panels and a 120 gal tank.
the system cost, with me doing my own install is about $4000.00
here again there is a state and federal tax credit write off of about 50% so the system
will cost me about $2000.00
I have been monitoring the system and calculating the heat it generates compared to #2heating oil at $2.19/gal (I have a #2heating oil hot water heater) I estimate it will take me 4 years to recoupe my costs on the solar hot water system. IF I had this system installed by a "solar installer" it would have cost $8000.00
in that case it would take me 8 years to recoupe the cost.

Also keep in mind that these systems will break down and if you are not handy and have to hire a solar repair guy to fix the system you may never recoupe your costs.

I wanted to post this info because I see all the misleading hype about going to solar to solve your energy costs. I have heard of people getting a second mortgage on their house to pay for this exspensive system and they will never recoupe the cost when you factor in the interest on the loan.

I have noticed that the word "SOLAR" is the same as the word "MARINE" (as in boating) you are charged a premium for it. The price of the hot water solar system I installed has gone up $1000.00 in the last 4 months.
I am sure it is because the tax credit has increased demand.


I hope this info helps

 

<div class='quotetop'>QUOTE(jimmyhua @ Jul 21 2006, 05:33 PM) [snapback]290146[/snapback]</div>

*I was looking at 48V DC for the solar panels, but it seems HV is very popular. I think anything > 100V is *very dangerous. But the more popular systems all run between >150 to 600V. Why is this so?

OK, there is a problem with efficency when you have low voltage (48V)
if you install 10-48v panels and run 2 wires from each panel 30 ft into the basment to the power inverters you will lose power in each wire run.
but if you connect the same 10 - 48v panels in series and run 1 pair of wires down to the basment power inverter you will have 480v and less line loss.
This is the same reason electric transmission lines are thousands of volts and reduced by a transformer at your house.

*Can I get a 5KW system first, but only put in 1 KW of solar panels, and add more later? What if later, the *solar panels that become inexpensive run at a different voltage than the ones I got? Can I mix and match?

If you looked at my install, you saw 4 red inverters mounted on the wall.
those are 2500u sunnyboys that means each inverter is able to make 2500watts of ac power.
each inverter is capable of handling 600v DC.
If you wanted to use 48v panels you would connect 12 panels together (these must be the same voltage and current) and run one pair of wires down to one 2500u sunnyboy and you would be feeding (12x48)=576v dc to the inverter.
this would give you about 2200 watts AC max (at noon time) You will never get the full 2500watts because of line loss and inverter converson loss ( the inverter will get very warm)
as the sun goes over at say 2pm you will be making about 1500watts
at 4pm you will be making about 700 watts

now, those 12-48v panels and one inverter are in a world of their own looking out at the utility line.
the inverter syncs itself to the 60 cycle sine wave of the utility company. that is how it feeds power back to the utility company. That is how the meter runs backwards , it syncronizes itself to the power company and if the power company is supplying 240v the inveter will generate 242v so your meter will run backwards.

If you want to add more panels you would buy another 12- 48 v panels and another 2500u sunny boy and do the same thing connecting it to the main fuse box.
the new sunnyboy has nothing to do with the first sunnyboy . the new sunnyboy will sync itself to the utility power and start pumping it's 2200 watts at 242v ac

so , yes you can start small and add to the solar system but you cannot mix differant panels together.
they all must be the same in the string, they also must all face the sun at the same angle.
note:
you may not realize that if you have a nice sunny day and the utility loses power the sunnyboys will shutdown. for safety reasons They are made so they cannot operate unless the utiliy power is there.
people assume that they will generate their own power.... not true



*Btw, electricity here costs 0.18 per KWH here, so I think I can make my money back faster than you did
I think you have it backwards. the electricity I make is worth more and I will get my payback faster.
(were not talking about much faster)

*If it's going to take ~25 years to re-coupe investment costs (not including installation costs). This is too *much. I was looking more at ~5 years.

Like I said before, if you reduce the size of your system to reduce cost, you also reduce the amount of power made , so no matter how you do it, the pay back will be 25years.
you might want to think about not doing a PV system but instead adding insulation ,new windows ,awnings and high efficency light bulbs, or high efficency air conditioner.

hope this helps

 

<div class='quotetop'>QUOTE(jimmyhua @ Jul 22 2006, 01:51 AM) [snapback]290359[/snapback]</div>

If you are still going to buy a PV solar system, make sure your electric company allows you to connect to them and generate power to spin the meter backewards. Other wise you will end up being a Guerrilla solar person, this is a group of people in the underground who illegally connect to the power grid to reduce their electric bill mostly because their set up won't pass inspection.
here is a link to more info:
http://www.homepower.com/magazine/guerrilla.cfm



a 2.5KW system will produce about $500.00 / year.
it will cost you approx $7/watt so 2.5kw will cost you $17,500.00 uninstalled.

you can get more output by installing the panels on a moving tracker that follows the sun.
some places require you to get building permits to install it.
here is a link to such a system, it will increase your output by about 30%, so yearly output approx $650.00
but you are also increasing the cost and complexity
http://www.wattsun.com/internet_only_special.html

 

syncmaster,

The info you provide is EXCELLENT. I have studied solar systems and am about to make a move fairly soon. Unfortunately, in California our incentives are lower than yours and getting lower still about every 6 months. Thanks for the great links too!

 

<div class='quotetop'>QUOTE(jimmyhua @ Jul 23 2006, 02:45 PM) [snapback]291045[/snapback]</div>

You don't have to buy some solar equipment to see what power you will get.
here is a link to a solar calculator.
http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/

you will see a the USA , Hawai and to the left --- Guam
click on Guam

Enter the size of the system you want to install
enter the angle the panels will be mounted at.
enter the cost of electricity
It will calculate your KW of your system for the year.
It takes into account weather and location.
I checked this calculator against my actual 10kw systems readings and I can tell you it is very accurate.

here are a few pointers that I think might help you.
check with your power company first before you buy anything.
if you are allowed to tie to their electric grid, you will probably have to submit a form that they will supply.
on the form you will state excatly what equipment you would like to install.
the power compwny will either approve or not. -- you cannot hook what ever you want. It has to be approved first.

If you buy a system from a internet company, you have a lot of leverage... use it . If you are buying 10 PV panels and a inverter you should get a large discount. Try to buy all your stuff at one time.
If the PV panels sell for $810.00 each and you are buying 10 plus a inverter , you should get the panels for $700.00 each, first decide the size of your system and then shop around for the whole system... don't buy pieces.
(this is where starting small and adding to a solar system hurts you)


Watch the shipping charges- you might get excellent prices from someone and then they over charge you for shipping.

The outback system you are talking about will need a bank of batteries.
Batteries are very exspensive , require maintenance, and I think they only last about 7 years.(not sure about the time).
But back up power is a nice feature.
You could instead hook up a backup , autostart gas or diesel generator.

The PV system must face south and have no shade from other buildings , nearby trees or even a flag pole.
any shade at all will cost you alot of wattage. If you look a the picture I posted above.
you will see some shade on the left ... during the summer I have no shade at all on my panels.
but in October when the sun is lower in the sky that shade ends up on the first row of PV panels.
So I get some shade from October to April, till the sun gets higher in the sky.
This is something you should look at.


You didn't mention a mounting rack for your system. But you did mention typhoons.
The mounting rack they sell are rated for 110 mph. I don't know what winds a typhoon brings
but I think you get the picture.

You might want to look into a hot water solar system.
IN guam I bet the pay back would be very quick and the system is alot cheaper.


hope this helps