Off Grid solar power solution.

4 Posts

Aug 15, 2006 07:59 am

Someone help. Frequent city power cuts. I would like to power my house by solar power using PV panels. My total load details are as follow: Volts x Amps is 7,848W
(230V x 34.12A) and Watthours/day is 46,301W/Hrs/day and 1,389kW/Hrs per month calculated using the provided calculaters. I live in a 220-250/380-415Vac zone.

Now have problems choosing components startin from PV through Battery bank, Charge controllers etc to Inverter. I can calculate circuitbreakers after the Inverter depending on load requirements.
NB: Need Sine wave, to power compurts/servers etc.
If possible quoted price.

All I need is a well configured sys. that will run smoothly/withstand a 3 day no sun after a full charge

Budget will not be a problem.

joe

Chris Brown

52 Posts

Aug 15, 2006 12:22 pm

Re: Off Grid solar power solution.

Hello Joe,

I have an idea of some components that might work for you. Please contact me directly via phone or email and I'll get a quote off to you with components that will meet your needs.

Thomas Hardy

30 Posts

Aug 15, 2006 02:30 pm

Re: Off Grid solar power solution.

Hello Joseph - you didn't give your location, but in the sunny US southwest (I ran the model for Albq NM) you would require approximately 12KW of solar panels to pull that off (requiring a lot of real estate for the panels!). In addition, you will require a lot of batteries to support three days. The racking, wiring and mounting of the panels and batteries will be significant, and you will also need the right inverter(s) and other equipment. Between hardware and installation costs you are looking at $100 -120K ! A better solution might be to go with a low cost automatic backup generator for those times when the power does go out; cost would be about an order of magnitude less than the solar. A hybrid approach (i.e. a backup generator and some solar) might be most cost effective. However, a lot more info would be required to perform the engineering analysis (accurate data such as how often does the power go out, for how long, your location, cost of electricity, any other special factors, etc.). I strongly recommend you have an engineering evaluation before you start spending the kind of money it will take to put up this size system.

Tom Hardy, PE
HVTA, Inc.

Chris Brown

52 Posts

Aug 16, 2006 02:51 pm

Re: Off Grid solar power solution.

It’s true that the amount of equipment you would need to produce 1400kWh’s a month is very site specific, yet I’m not convinced that a fossil fuel powered generator would necessary be a better solution. Many of our customers choose renewable energy as a life style choice and have ethical and moral reasons for choosing solar electric power for their homes. Other customers live in areas where fossil fuels are difficult to acquire because they are in a remote location or the price of fuel is cost probative (according to CNN Money Report the cost of a gallon of gasoline in Europe is over $6.00). There are also clients who enjoy the security associated with producing there own power and are supportive of domestic energy. Other people live in areas where the government offers state incentives and rebates that can considerably offset the startup costs associated with a renewable energy system.

No matter what the reasons are for choosing a renewable energy generator over a fuel dependent generator it is certainly true that reducing consumption and conserving electricity are great first steps to reducing the up front costs associated with such systems. Energy conservation can be as simple as using compact florescent lights and energy efficient appliances and in general becoming a conscience electricity consumer. When investing in a renewable energy system you are in essence ‘prepaying’ for your electricity for the next twenty or so years; therefore even very small reductions in consumption on a daily basis will have rippling effects on your initial start up costs and long term needs.

Tom is correct in saying engineering evaluation is in order before making such a purchase. There are very few ‘cookie cutter’, out of the box renewable energy packages available, especially when talking about this scale of energy production. What Joe needs, in my option, is a custom, tailored system to meet his individual needs. Either one of my colleagues or I at the Alternative Energy Store would be happy to help in selecting components for a system of this nature.

« Last Edit: Aug 16, 2006 04:47 pm by Chris Brown »

Joe Felix

4 Posts

Aug 16, 2006 07:03 pm

Re: Off Grid solar power solution.

Hi Guys, I very much agree with you. I live in Denmark but need the solar solution most for my business in Kampala Uganda. Power cuts there is often & some times for 3 days in a raw/fosil fuel alike. Beeing almost on the Euator line, gives a daily sunshine with minimum sunshine 0f 6-7 hrs a day in August-September. I´ve 2 generators 25/60kVA but use alot cash on fuel. I would be grate if I could get the complete configuration compnent listing/cost & compare with runnig generators/ON/Off business.

I could also scale out loads like ACs/electric stoves & just have lighting/computers etc.

Just send me something around the US $120ks.

Thanks.

Brian Hansen

1 Posts

Aug 17, 2006 04:20 pm

Re: Off Grid solar power solution.

I agree with Chris when he notes that:

Quote from: Chris Brown on Aug 16, 2006 02:51 pm

No matter what the reasons are for choosing a renewable energy generator over a fuel dependent generator it is certainly true that reducing consumption and conserving electricity are great first steps to reducing the up front costs associated with such systems.

But I think he may not have gone far enough. 50 kwh per
day is a pretty high load for a single home (in my opinion).
You could probably reduce that load a great deal by
changing to CFLs, replacing appliances, improving the
passive solar aspects of your house, and checking out
solar domestic hot water. I would be surprised, if your
situation is typical, if you couldn't reduce your load
by one half or more with these techniques. This could
put you at the level where federal, state and local
incentives and rebates could reduce the cost of the
overall system significantly.

« Last Edit: Aug 17, 2006 04:22 pm by Brian Hansen »

Thomas Allen Schmidt

679 Posts

Aug 18, 2006 05:11 am

Re: Off Grid solar power solution.

I've read that sharks have a sense of when other fish are in distress, they can use this sense to zero in on their prey. Buyer beware. PV is a sellers market. With that aside.

Seeing as how you are on grid, all be it unreliable, it can be utilized to maintain a lot of the charge to the battery bank. Great care should be taken to size it right the first time though so get someone you can trust (an electrical engineer preferably) to do a load evaluation for you if you don't feel comfortable doing yourself.
47,000 watt hours a day or 47 kWh. I take that as a 24 hour period. In terms of amp hours of battery storage at 48 volts nominal that would be... might as well 1,000 amp hours over a 24 hour period. You say you want 3 days of ups (uniterupted power source). So 3,000 at 48 vdc nominal but you do not want the batteries to go completely dead doing this. If they are taken down to a 50% depth of discharge that would necessitate a 6,000 amphour battery bank at 48 vdc. A heavy steel flywheel generator could reduce the size of the battery bank but not the cost of the system. PV can also reduce the size of the battery bank but only during the day of course and again not the cost. A minimal size PV array can be installed and then in time more PV modules added to the array. Picking which loads you cannot absolutely do without and the amount of time you cannot do without them can reduce the size of the battery bank as well.
HUP Solar One (nwes.com) advertises a 48 volt battery bank at 1,690 amp hours at the 20 hour rate for $11,296.00 US.
The load the you stated would require at least 4 such battery banks at a 50% depth of discharge over 3 days. Not to mention shipping and handling, cable, and subsequent electrical safety equipment. Oops! I am out of time. Gota go.

Joe Felix

4 Posts

Aug 18, 2006 10:58 am

Re: Off Grid solar power solution.

Thanks allot Thomas Allen Schmidt/the rest. I´ve got to cut down on my load and back-up time to 1 day and see what would hhappen Still that leave with the problem of configuring a small sys. of aapprox. 30kkW hrs.

Thomas Allen Schmidt

679 Posts

Aug 19, 2006 07:20 am

Re: Off Grid solar power solution.

Here is some information about those heavy flywheel generators I mentioned.
http://www.globalspec.com/FeaturedProducts/Detail/ActivePower/Cat_UPS/4486/0
There is also the microturbine generator which can utilize methane from wastes as well as provide a significant heat source for such things as ammonia adsorption chillers, sterilizers, anything that requires temperatures of around 500 degrees Fahrenheit.
http://www.microturbine.com/
It may be beneficial if community monies were "pooled" in an effort to create a local electric cooperation utilizing microturbine generators with heavy flywheel generators to increase the reliability of electric power to the entire community. This may or may not be of intrest to your local electric power producers. After re-reading these posts I got the opinion that the electric power producers in the area you refer to, Uganda, may be in need of some electrical engineers to help with the reliability of their electric power production and transmission line infrastructure. I am curious, have they mentioned any reasons why there are so many power disruptions? What is there main fuel source for electric power production; coal, petroleum, nuclear, other?

I can also imagine a system that could send a signal via higher frequency in advance of an impending blackout and warn the community. I have participated in the installation of similar systems that would warn industries of an impending time of use rate increase which would give them time to shut down the plant and save them tens of thousands of dollars in electric energy costs. The down time and loss of production is less than the time of use rate increase.

Thomas Allen Schmidt

679 Posts

Aug 19, 2006 07:52 am

Re: Off Grid solar power solution.

A bit of news concerning electric power I just discovered about Uganda for anyone interested!
http://www.allbusiness.com/periodicals/article/1183719-1.html
It would seem that they want to encourage the exploitation of solar energy.
One thing would seem certain, whoever is responsable for the mining of raw silicon minerals from our Earth for the production of PV cells could become, if they haven't already become, one of the, if not the richest, aristocracies this planet has every known. Their future for generations to come is secure, that I do know. Dare I compare it to other aristocracies that have gained their fortunes by striping our Earth of a natural resource such as trees, or fossil fuels, fresh air, and clean water? I guess time will tell!

Joe Felix

4 Posts

Aug 19, 2006 04:10 pm

Re: Off Grid solar power solution.

Hi T. A. Schmidt, thanks again, there is alot I didn´t know. But this is a real food for thought you´ve given me. I´ll keep reading & would like to hear more about the high frequence warning sys. might be of a grate use in Uganda.
Keep arround.

David Hughes

8 Posts

Aug 25, 2006 11:02 am

Re: Off Grid solar power solution.

[This post has been removed by the moderators]

Please keep personal attacks out of this forum. We would like to create an open, welcoming atmosphere, where everyone is welcome to post with out it being personal.

Thanks for your cooperation, = )
-Nick

« Last Edit: Aug 25, 2006 01:07 pm by Nick Albright »

Arcandspark

29 Posts

Sep 15, 2006 06:38 am

Re: Off Grid solar power solution.

I installed a system for a freind that lives off grid. Three bedroom mobile home, full kitchen, three window AC units, water pump, sat. TV, computers, modern living. Since 1999 they have been enjoying the good live. Now they are having me help to build a 3000 sq ft home on the same site. Currently I have a dual Trace SW4024 inverters with two 24 volt 1500 amp hour battery banks, 22kW generator for back up andsolar panels, and wind generator. I am building a heat exchanger to use the waster heat energy form the generator from the engine coolant, and engine oil which both run about 190 to 200 degrees. This heat will be stored in a phase change tank using about 300 pounds of plumbers solder (tin/lead) which will store the heat for hours and then using hydrualic oil I can transfer the heat from the tank into the house to heat the domestic water heater, and even use it to help heat the house during winter. It is called Co-generation and has been used for decades on ships and large boats. I had planned on using the engine exhust but at around 1200 degrees the cost to store the heat and transfer it becomes much more expensive. At around 200 degrees I can use off the shelf items to control the temperature to a much safer level, around 140 degrees for the transfer fluid which will last much longer at this temperature (years) before starting to degrade. The dual Trace system has been working fantastic since 1999, the only problems have been generator problems. The only advice I can give would be do not use Kohler generators and always use a low RPM unit (1800 RPM) not a 3600 RPM unit.
Capt.arcandspark

R. Stephens

9 Posts

Sep 15, 2006 10:10 pm

Re: Off Grid solar power solution.

Hi Joe,
If you still need help, let me know.
Where about does you business located?

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Off Grid solar power solution.

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