Newbie to Solar power and very impressed with this Forum

stephendv wrote: »

Hi Piet,

Welcome to the forum, I'm an ex-pat saffer from Bloemfontein Regarding your system, I think a semi-off-grid solar setup is a good bet because your usage co-incides well with solar irradiance.

It'll be good to know how long the power outtages are, because if you have the grid available most of the time then it will be much cheaper to buy batteries that just cover 1 day's use. Usually those of us who are pure off-grid will size the battery bank to last for 2-3 days before we have to turn the generator on. This increases the cost of the install considerably.

In Spain the price of electricity continues to rise and it's becoming quite popular to install semi-off-grid systems where the battery bank is cycled daily and is sized for just 1 day's power. Any deficit is then made up for with the grid. I highly recommend forklift batteries because they're the cheapest over their lifetime, i.e. the cost/kWh/year is the lowest of most batteries. And you're likely to find a source of forklift batts locally. The disadvantage of the forklifts is that they come in a single big metal container, which could weight up to 1 ton and it's difficult to remove the individual 2V cells, so you really need to be able to drive up to the place where you want to install them and then have a crane or forklift to unload and install them. But they're very tough batteries and are usually rated at 1200 - 1500 cycles at a depth of discharge of 80%.

You should be able to find chinese solar panels for around R10/Watt, and possibly cheaper if you can go directly to a distributor. In terms of inverters, I think SMA (Sunny Island) are sold there and possibly Victron, both good quality units.

The heat pump + geyser (hot water tank for US folk), is interesting because it'll let you time shift the usage. I.e. only turn on the heat pump when the sun is shining, which means you can go with a smaller battery bank.

westbranch wrote: »

Geysers are smaller tanks than we are accustomed to. The ones I saw were 2 - 5 gallons, so quick to heat... I have to imagine they might have even been able to 'vent' in the early days, 1950's according to my wife, who hails from Scotland .