pv solar modules

The main drawback is night. You'll need batteries, which you don't need with a diesel system. Adding a battery system has a host of cost and maintainability issues that you don't have with a simple generator system.

The major drawback in many countries is the initial investment. Do a comparative investment study. Some Indian companies can be extremely cost effective for South Africa. You have to incorporate a good charge controller, inverters and batteries. As pv power generators are non mechanical and electronic controlled delivery system they have no major drawback and should last you 30 to 50 years. Will be glad to help you out on hearing from you on ckusbd@gmail.com

Our solar system can do some. Please contact with us. Henryzhang1@hotmail.com

It is always about doing a trade-of between budget and performance. But everything starts from load evaluation. You have to draw a chart of energy consumption/24 hours by category (air conditioning, lighting, etc.).

The best is to build a hybrid system containing:

- solar photovoltaic (PV) panels (generate DC) + battery bank + inverter/charger (generate AC)

- solar thermal panels for warm water and air conditioning (evaporation system)

- diesel back-up generator (to charge batteries).

Sizing correctly each component will bring the best cost effective solution to your project. Another good practice is to save as much energy as you can by using efficient lights (LEDs are the best) and appliances, laptop computers (with individual solar chargers) instead of desktop, etc. Also you can schedule irons and hot plates to be used only around noon when PV generates most power. Change energy consumption habits having energy savings in mind!

PV panels are the most expensive, so building like 30KW of PV is the worst idea. Mounting them on a tracking platform will bring 30% more generated power. Probably you won't need more than 8-10KW PV panels on a solar tracker.

The battery bank is sized by hours of autonomy (dark time and cloudy days) and has to be thought in conjunction with the diesel generator. Let's say 5 hours of dark time to power a 5KW load. If the previous day was not very sunny and batteries were not fully charged, than the generator starts to cover the next morning needs for 2-3 hours (but let you sleep in the night!).

Already having the diesel generator is an advantage. Start building the hybrid system around it, according to your budget.

Thanks, but the air conditioning, water heater, lighting, tv, small fridge is available in each en-suite room of the guest house and cannot control how the guests will use it so I'm assuming 24 hours use (either solar and diesel generator/utility). Still don't get the point about how drawing a chart of energy consumption will help, as i've estimated the load to be about 28KVA and we have a max of 10 hours sunshine on a really sunny day.

Don't forget!! Solar panels produce DC. If you expect to run standard appliances, you will need a pretty healthy inverter to convert the DC back to 240 volts 50Hz AC. I don't know if they make them to handle 30 Kw (which would be 125 amps @ 240 volts).

Bill

Hello,

May I suggest tying the generator into PV array and use the suns energy during the day and the gererator at night when the loads are typically minimal. You would still need a minimal battery back up system while your generator gets up to speed and for minor cloud brown outs.

If you have any questions email me @ wpkenney@lbl.gov, P.S. tag the message or it will get filters.

good luck.

Also this website has some good information American solar energy society