Day in the life of solar geek Bernard Preston

Day in the life of solar geek Bernard Preston is about using the sun's energy to our own advantage.

It's 5.30 and another day in the life of solar geek Bernard Preston; as is my custom I start simultaneously doing my lower back exercises, and saying the Lord's prayer in Dutch. Who says a male can't do more than one thing at a time?

Anyone who sits a lot, as I do at this computer, or does physically hard work but doesn't like pain, should do these little exercises; they take less than two minutes. You can find them using the search engine in the navigation bar.

Then I like to keep my Dutch up to speed; it took so much energy and commitment to learn it, that I don't want to lose the language. Listening to classic FM at my computer keeps my ear well tuned into good music and the third most difficult tongue in the world.




This is a long and perhaps arduous page outlining just what you can expect from your sunshine PV panels; photons of light are captured and their substantial energy is turned into a usable voltage.

A leaf of lettuce does something similar but using a different process called photosynthesis.

Before I turn on the inverter, I check the battery voltages. They read 51.2V which means they are 82 percent full; that's fine. Already light is filtering in and the photovoltaic panels are registering 25 watts; it's going to be another hot and sunny day in Africa.

I carefully wash my face, hearing the reservoir pump kick on, but it's still using mains power. It would drain my relatively small battery bank unless there is full sunshine. Yesterday I did a foolish thing and had an unfortunate encounter with an African killer; it cost the bee her life, and I have a swollen eye. I rinse it carefully.

At this hour there's only enough energy coming from the eastern sky for LED lights and an Apple computer, or any laptop. Treading the stairs, tray of tea in hand, I quickly scan the daily bad news and emails before writing a chapter for my next book; its concerns the first married pope in a millennium. You'll get to read it in a year or so. Meantime Bernard Preston has six other books to entertain you.


Day in the life of solar geek Bernard Preston

Day in the life of solar geek Bernard Preston looks at just what this electricity can do in the home.



It's 7am and I hear She who must be obeyed is stirring. I peer quickly to be sure, and yes, there are now 600W arriving from Mr Golden Sun; the first direct rays are reaching the panels.

I flick the change over switch, moving the whole house over to the solar generator. We have to be careful and conservative with electricity for an hour until the photovoltaic panels really start churning out plenty of free energy; still, there's enough for a pot of filter coffee.



I have a manual solar system. You can for a handsome fee purchase a fully automated generator. Mine is home built; cheap but not nasty.

The total cost was about 13,000 dollars, but a third of that is the batteries; in a country with reliable clean electricity you could be grid tied instead.





Perhaps I should say cheaper; thirteen thousand dollars is a fair sum but, as you will soon read, it really performs well. Our total electrical usage from the utility is about 50kWh per month, mostly for LED floodlights and the reservoir pump at night; toilets must be flushed and sometimes after a hot day in the life of solar geek Bernard Preston, digging potatoes, or splitting firewood, he needs a shower after sundown.

So, using the solar generator, I grind the beans, brew the coffee and froth the hot milk. Living for seven years in Holland cured me for ever of instant. The percolator draws 900W for a short time and the system handles that with ease, even at this early hour.

Before long my wife and daughter have two washing machines running simultaneously; they don't draw much current, using water from the solar hot water geyser.


Another sunny day in the life of solar geek Bernard Preston


A long and indulgent hot water shower costing nothing is one of the benefits that a solar geek can look forward to; the lovely soft rainwater is captured and stored in our rainwater reservoir; the self priming pumps are driven by the sun. It leaves zero carbon footprint.

I don't buy into the philosophy that we must be exceedingly stingy with our water; by reorganising your home, you can enjoy half an hour in a shower like this with no detrimental effect on the environment.


Whilst they are busy, I spend about five minutes throwing in the makings of our homemade loaf; it only takes few moments to prepare the dough and get it into the solar electric breadmaker; it draws very little current until the last 50 minutes in the baking cycle; that's just before noon when there is plenty of energy from the sun, even with the solar pool pump on continuously.


Every day in the life of solar geek Bernard Preston, he starts with three cups of tea, a pot of filter coffee and then we enjoy a hot breakfast, so it's not long before I have an onion frying in butter on the portable induction stove; that's a must whether you are going solar or not. It works faster than gas and uses less than half the electricity of a conventional spiral plate.

In another few minutes I'll be adding the makings for eggs Florentine; a must if you lack energy, are concerned about your cholesterol, or are banting. That's the easiest way to lose weight. Type it into the search engine below.



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The induction stove is a must for every family; shop around and you can find them for around $30; that's what ours cost from Aldi in Holland.


And of course, the toaster too works on solar energy; it draws quite a lot of current but only for a short time.

It's 8.30 and there are 1400 watts coming in now from the sun, so I flick on the swimming pool pump and chlorinator; together they draw about one kW and they run for most of the day, unless we are using any other heavy equipment like the electric mower, or my carpentry tools.





It's a lazy Saturday morning in a day in the life of solar geek Bernard Preston; with no chiropractic patients, after a leisurely breakfast we stop and discuss matters. Shall we rinse everything by hand, or use the dishwasher? The latter gets the nod which lets me off the hook.

My daughter puts on her dishwasher; in the drying cycle that does draw a lot of current; the last ten minutes or so. It's also fed with hot water from the solar geysers.

All along the swimming pool pump and chlorinator were running; they draw together about a kilowatt. During the last ten minutes of that dishwasher cycle I thought it was wise to turn off the pool pump, just to be safe as a cloud or two had drifted across the sun. You don't want to hammer the batteries; they are the most expensive item in a solar generator, so you need to care for them.


Then it was time for Helen and I to take showers, that reservoir pump draws 750W, which is no sweat. A long indulgent hot shower is one of the luxuries I allow myself; free rainwater from the reservoir, heated yesterday by the sun and stored in the hot water heater, and no cost electricity from the sun to drive the pump.

Then the breadmaker came on just before lunch; it draws nearly a kW but in bursts so there is plenty of energy at midday.

After a few chores, it's time for a cup of tea; that kettle draws a heavy 2.2kW but it's only for a couple minutes; there are by 11am nearly three kilowatts of energy coming from Mr Golden Sun. The inverter handles it with ease, and the batteries hardly dip, despite the pool pump being on.

The clouds have cleared off so I have no concerns when I hear the bread machine come on to the baking cycle; the sky is providing a steady 2.7kW so there's plenty of energy.

It's the heat of the day, so the two fridges and a deep freeze are drawing current too, but not much. It's all about managing your power usage.


A day in the life of solar geek Bernard Preston

Watch your toes and the cord, Bernie! If you have a 10kW inverter you can power anything in the home. The only item I don't use is the inverter welder, not because the current is too high, but because of the arcing.


Should a day in the life of solar geek Bernard Preston include mowing the lawn? It's hot and humid and I feel like a good book and siesta after lunch. Instead, smitten by my conscience, I get out the solar electric lawnmower. It draws 3kW and the pool pump must go off first; that's no longer necessary as you can read lower down since I've added three more large west facing panels.

In South Africa we are gravely concerned about the real possibility of a total blackout; if I was to build a solar powered generator again, I would do it differently. Instead of putting the photovoltaic panels on the roof I'd build a dedicated extra workshop, using the PVs as the roof cladding. Then I would have room for another eight or twelve panels, and there would be none of these concerns about too many appliances on at once. Five to six kilowatts would be ideal.


A gas hob is ideal for those rainy days, should there be a utility rolling blackout, as happens frequently in South Africa. Then we simply can't bake with the solar electric oven, but we do have hot food.

My daughter knows she must get dinner into the oven before 3pm if she wants it cooked for free. I hear her busy with a couple chickens, potatoes, onions and butternut. During the time the solar electric oven is heating up, she turns off the pool pump for about twenty minutes; once the oven is hot she can turn it on again. 

All through the day the modem, router and computers will be on periodically but they use very little current; television too if there's cricket on, but it's a rare day that we watch TV during daylight hours. There are too many other far more exciting things to be done; I prefer having fun myself to watching others enjoying themselves.

It's 4.30pm and it's an important moment in the day in the life of solar geek Bernard Preston; he turns off the solar swimming pool pump, and returns the change over switch to mains; in the event of a rolling blackout, with full batteries we would have energy to go through the evening, but it stresses the batteries and shortens their expected life of about ten years; we use mains at night for cooking. I'm like a mother hen with the batteries; they are very expensive. I'm hoping there will be new developments in a decade when I'm again in the market.

We will have an electric car by then, I could even use its battery as a backup for our home at night; even now, I'm looking at Zero, the electric motor cycle that can do 0-100 in 3 seconds; it's still to expensive for me.

Buy LED light bulbs

Buy LED light bulbs is the first step in anyone wanting to save money and use less electricity.

9pm. It's bedtime after a long day in the life of solar geek Bernard Preston; it's time to turn off the computers and most interior lights; the outer floodlights remain on mains all night. Only buy LED light bulbs for your home.

I turn off the big 10kw inverter, noting the batteries are still 90% full; it's been a good day in the life of solar geek Bernard Preston. It could be a good day in your life too!


Could you be a solar geek too?

Yes, you could build a solar powered generator too provide you are reasonable with your hands, and are ready to talk to the experts and get advice; you'll find many of them feel free to help you. I'm not an electrician but I do love to tinker.

Here are two important tidbits; plan to go big from the beginning. You'll find the greed factor kicks in when you realise all this solar energy is free; you'll want more of it. The solar powered generator upgrades that I went through are quite unnecessary; and costly.

Go straight to a 48V system when choosing an inverter for home. Lower voltages are available but that means high current and big losses; and the inability to expand your arrays of panels.

However, think first about the 12-24-48V solar generator. It will mean the added cost, but also much greater efficiency of four batteries as against only one.

Consider putting the PV panels on the ground or making them into the roof of a dedicated workshop or extra garage; I might still do that. Watch this space!

I've built this solar generator for a number of reasons; best of all though these days in the life of solar geek Bernard Preston have been a lot of fun. I've enjoyed every moment, and am still loving it. And reaping the benefits of reliable and cheap electric power; pay back time is estimated to be 10-13 years by some but I'm thinking shorter because I have the best batteries and never drain them, and we never have electronic equipment damaged by surges.

That's excluding the damage done by dirty power from the South African utility, Eskom. Many folk have had TVs, computers and fridges blown by the surges and brown outs. Their poor management, and racist sidelining of competent engineers and managers has now resulted in their stock being downgraded to junk status; to build new power stations they have applied to the energy regulator for a 23 percent increase in the price of electricity. The real payback time, taking all these factors into account is really 7 to 10 years.

Update: They got their 23%, and this year it's 16%.


Is there anything that solar can't handle?

Not really; my big 10KVA inverter and 4.1kW of PV panels are up to virtually anything. The only device I don't like to use is the thicknesser/ planar; it jams now and then, and then the current skies.

And my welder; these new inverter welders draw amazingly little current, but I'm a little anxious about the arcing. That Big Boy cost a lot of money, so I weld on mains power.

Mm, having said that, supplying power to two homes is needing more panels now; I'm cogitating.

Until I have more PV panels I just can't run everything at the same time without thought or concern.

Of course, when the three day spring rains arrive there'll only be enough for computers and lights; so we haven't gone off grid. Yet; and probably never.

Update: As you've realised we are powering two homes, and now that ovens, dishwashers and hot water kettles are being used, there's not enough energy for the swimming pool; more west facing PV panels are in the planning.

Update: I've just bought three very large panels supplying 305W each; they get more powerful and cheaper all the time. More about them in another blog on a future day in the life of solar geek Bernard Preston.

With 4.1kW of sunshine my system is now big enough; all I might one day consider is becoming grid tied, but that's not legal currently where I live. We do have a small excess periodically when the dishwasher and breadmaker aren't busy that could be pumped back into the national grid.


Changing fluorescent light fittings to LED

Whilst replacing most incandescent bulbs with LEDs is absolutely routine, a small change has to been made to a fluorescent tube fitting to accommodate an LED tube. Having said that, changing your fluorescent light fittings to LED is really very simple. All you need is an electrical screwdriver and a short length of single core copper wire.

Just another day in the life of solar geek Bernard Preston. You could be a nutcase too, but do switch off the mains before fiddling.

My wife's an Agatha Christie fan and she's got the perfect murder all worked out. Wait for yet another day in the life of solar geek Bernard Preston and when he's working on one of his electrical problems, turn on the mains! Now I have to wait for her to leave the house before venturing to do a solar job.


Going off the grid

Going off the grid is a bit of pipe dream as far as I'm concerned. Unless you have enough dollars for a very large battery bank.

And even then it's cold showers if you have an extended period of inclement weather. That's the opinion anyway from a day in the life of solar geek Bernard Preston; others have their own ideas.

Another serious disadvantage of going off the grid in a country with an unstable utility that resorts to load shedding is that it also causes the inverter to shut down to protect any electricians working to repair the systems; despite the fact the sun is shining brightly, you are still unable to utilise solar power.

This dilemma is discussed fully at another blog at grid tied residential solar power. The long and the short of it is that you need a second inverter and a battery bank. My advice if you are living in a country with an unstable utility power supply is not to go for a grid tied system. Rather use a change over switch to toggle back and forth from solar to the grid; you cannot put energy back into the grid, but for the majority you only have a small surplus anyway; the extra cost is not justified.


West facing panels

When the idea of facing a portion of my array directly west arose, instead of north, I immediately saw the sense of it. We have more than enough power during the day, but not enough in the late afternoon; in the early morning too. That means more challenges for the next day in the life of solar geek Bernard Preston.

First I had to consider the effect of shadows on PV panels and, having discounted that, I'm about to put up three large west-facing panels. Watch this space!

The 300W panels are purchased, the frames have been welded and now they must be erected. That's no mean feat a story up on a west facing wall.

West facing solar panels are something different.

About another kilowatt of east facing solar panels are in the offing too to give us plenty of early morning power for cooking our breakfast.

Unfortunately they are also going to mean an extra MPPT. My 60A draws close to the maximum, and the new panels will add an extra 20A of power. The sunshine is free, but collecting and storing it does cost a pretty penny; it's still cheaper and more reliable than the utility though.

Finally the decision was made to put the panels not on the wall but on the west facing roof; it was the right decision. Those three panels, in total 915W produce more energy than the 3200W of north facing PVs in the late afternoon; a very needed boost when the oven is often going on.

Days in the life of solar geek Bernard Preston are busy; are you too enjoying a full retirement, or does time drag and you keep getting under the wife's feet? Think about these retirement sentiments. I've just spent four days soaring the mountains in the hinterland of South Africa in a glider; your days too should be filled with something absorbing if you plan to live long in the land.

Gliding and the garden are what turn me on, after tinkering with the solar generator; mm, how could I forget the bees. Even our easy homemade vanilla ice cream is made using solar electric appliances. 


Mobile solar panels

Right now solar geek Bernard Preston is having fun with a new project; I want to have my morning coffee using sunshine, and she who must be obeyed hasn't enough power in the later afternoon for dinner. So I'm building mobile solar panels using a little buggy. Watch this space for more details to come.


Refrigeration using solar power

Cooling in the home, airconditioning excepted, draws surprisingly little electricity and of course it's mainly needed during the daylight hours when your solar generator is pumping. In our two homes we are needing refrigeration using solar power for four fridges; they draw very little at night when it's much cooler.

Today, purchase only a new fridge using inverter technology; they draw half the current over a year, the variable speed motor idling most of the time. 


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What's this site about?

Bernard Preston books

A family affair by Bernard Preston

Consulting a chiropractor

Femoral nerve AP Xray

Bernie's healthy choice foods

Cooking green beans Bernard Preston passion

Bernie's bread

Bread machine loaf by Bernard Preston

Bernie's garden

green beans and granadillas Bernard Preston

Bernie's bees

Bees workforce in Bernard Preston's garden

Bernie's solar

Residential solar panels at Bernard Preston's home

Bernie's glider

View from Bernard Preston's glider