Lithium batteries are in 2019 the best way to store electrical energy. There are many new types coming on to the market but they at this stage are still more expensive and less proven.
This page was last updated by Bernard Preston on 12th July, 2019.
Lithium batteries are far more compact and enduring than lead cells and at last becoming much cheaper.
I am on record, several times in this column, of speaking out against
going off the electrical grid. The a mount of money that you would have
had to spend on batteries made it nonsensical, unless you have very high
line charges. But times have changed.
Two of the factors favouring going off the grid have not changed. The price of municipal power continues to soar, and its reliability leaves much to be desired. Whilst blackouts are less common due to the shrinking economy, power surges damaging our appliances continue; the cost of damaged computers, TVs and other sensitive equipment must come into the equation.
But the other important driving factor has changed dramatically. You can now buy a SA assembled 48V, 7400Ah lithium ion battery for R45,000. That’s a lot of storage capacity, and quite adequate for the average home unless you want to run the oven and dishwasher at night.
Lithium ion batteries have many advantages.
Firstly, they are relatively small and compact compared to the old lead type batteries, without all the many interlinking connections to get the equivalent amount of storage; that makes them safer too. It fits into a cabinet 600mm square x 190mm deep that can be attached to the wall.
Secondly, they can be safely cycled far deeper than a lead battery; one dare not take the latter below 50% if you want them to last, but a lithium ion battery can be drained to 30% of its capacity, and some say 15%. It comes with a 10 year warranty; you’ll never get even a quarter of that for a lead battery.
Thirdly, it’s a sealed unit with no odours or gas emissions; it can be safely installed in your house. There’s an interesting Australian battery that is proving popular called Redflow but far more expensive and it does give off some gas.
Fourthly, at the same voltage from the solar panels, a lithium battery can accept a far higher current; it charges much more quickly, and can be discharged faster too without a drop in voltage.
I suppose I should thank the Municipality for sending us that 431V surge last year that did so much damage down our street. It was the last straw, and drove us to reconsider our aversion to going off the grid, and to look at the new battery technology.
We have used 10c of municipal electricity in the last three weeks to heat the shower on a cloudy day. Installing a gas geyser will probably be necessary for the occasional misty days, but we are ready to go off the grid. Good riddance Eskom and the Pietermaritzburg electricity department with all your woes. Voetsek! Around R200,000 would enable you to do the same.
The next step is an affordable all-electric car that can be charged for free; there’s alas nothing that I can see in the pipeline; they all seem to be half a million and more, with the Nissan Leaf at the bottom of the range. Surely there’s an opportunity to be had for a SA manufacturer willing to test the market with a ‘people’s car.’
Best of all, by going off the grid you will be doing your bit to preserve the planet for your children’s children.
We are essentially two families living in two houses, so we decided to install two of the batteries. Yes, it was costly, but when you reckon on no electrical bill for seven people, the extra will soon pay for itself.
If only because of the convenience of ample clean electrical energy.
We still have these eight old lead batteries, using them as a backup on a rainy day, if needed. They are used daily or would sulphate up. We will probably dispose of them in the near future.
Return to solar power energy home page.
Lithium battery at Wikipedia.
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