Hello all, I need some help and advice. I am a brit living in Madagascar. I am setting up a luxury caping business and am trying to make it Carbon Neutral (this will be supplemnted by a tree planting project).
I have a Mercedes 1617 truck, which when running can be used for power,I then wanted a solar system to run the following: 3x Camping Fridges very low consmption (3 Amps per hour each) I will then also need to charge 12 deep cycle batteries. I know frustratingly little about electrics, and am struggling to find anyone here wih the required level of knowledge on such technologies. Are there any websites that can help me work out my power requiement, or do any of you have advice? I will have a 2kw Generator as back up and obviously everything will be on 12/24 volt systems. Sunshine is not a problem for 90% of the time, so the jenny is for back-up only. Any advice on Solar panels an how I might look to manage the circuits and charging? Cheers, edd
Tony
posted on 04-02-07
The best plan is to use the solar powered pv panels to charge the batteries and then take power from them. This arrangement has some inefficiencies but as your energy supply is free this is not such a worry. Sometimes large offices here in the Uk run the mains into a large bank of lead acid batteries and use them to run everything. This is known as an uninterruptible power supply (ups). When there is a power cut their own generators start up and so no one ever knows if or when there was a power cut. You could possibly buy a small ups and build it into your system and run everything on fairly much normal ac. Direct current is only any good over quite short distances.
You will need to calculate your own loads and size your pv array accordingly.
Tony
posted on 04-02-07
Also you then use the generator to charge the batteries too.
Edd in Madagascar
posted on 04-02-07
Thanks Tony just what I wanted to hear! So effectively I can use the Truck Engine (when we move) and the Solar panels to charge up a battery bank which then runs everything as a constant energy source - using the jenny to top up if it gets low. You are recomending me to do this using 220-240V AC current rather than a DC 12v/24v. So this would work - i.e. I can use Solar and the truck to charge an lead battery that would give me a 240V output? I had thought of the 12v/24v as that is what the truck uses - but you are saying I can get 240V battery (or similar)? The problem obviously is the fridges have to run through the night (when the solar and truck won't), so I need to have 12hrs of battery charge - on 240V? The jenny is a bit noisy and also as I want this to be eco-frindly running it all night is not really a good option, i can have plenty of solar panels so it is power storage and output overnight that is the key?
Thanks, I wish I had paid attention in Physics lessons when i was a nipper! PS sorry for the Spelling, French Keyboard!
Tony
posted on 04-02-07
The power from the batteries comes out as direct current but you then pass it through an inverter to bring it up to 240V ac. This kit will come as part of the ups.
Bernard
posted on 04-02-07
Invest in 12 or 24 volt fridges. Motor less evaporation cycle fridges are the type to consider.
Running a fridge with a motorfroma UPS is not effecient. The UPD produces a squarish waveform instead of a since wave.
PC power supplies ( which no longer have 50 Hz transformers ) are quite happy with the waveform from UPS. Equipment with motors or transformers become very in-efficient when power by square wave 240 volts AC.
A UPS tha give a near sine wave output will be less efficient
