Some lessons learned living with green energy

One of the ways in which suppliers promote the take-up of solar and wind energy systems is by saying that these are the best options for free environmentally friendly energy. Well, in actual practice, our solar energy system hasn’t been entirely free. For  water heating in the summer, yes indeed, solar is fantastic. For the use of most household appliances, the issue becomes rather complicated. But first a bit of background. I’ve been an advocate of alternative energy sources since the 1980s, and a priority for us in Spain was to install our own solar energy system.

Fortunately the cottage we bought has an off-grid power system, installed by Solar in Spain (based in Oliva, Valencia). The system consists of nine polycrystalline solar panels with a 24-volt bank of photovoltaic batteries. (I believe the panels are German-made Pairan.) As back-up on cloudy days, there is a 400-volt diesel-powered Lombardini generator. (Yes – Spain is usually sunny, but up here in the mountains we do get grey days even in summer.) For several mornings now, we’ve been without electricity. The generator is set up to automatically go on when there’s insufficient energy stored in the batteries, but for some reason it didn’t.


The solar panel with tank in front for hot water. Those behind are for electricity.

We called Solar in Spain, the go-between with the generator installer, Tecnics Grupos Electrogenos of Gandia. The lady in charge assured us that the technician would try to drop by that day as they had two jobs nearby. If because of time constraints he could not do so, then definitely the following day. So we waited patiently. Let me continue with the details of our energy system in the meantime, and the lessons we’ve learned.

For hot water, there is a separate solar panel with a tank of 160 liters, which is more than sufficient for 2 people. There is a propane gas-powered boiler for back-up. A wood-pellet burner powers the radiators for central heating, and there is also a wood-burning fireplace in the sitting room. The cooker works on propane gas, but the oven-cum-microwave, dishwasher, and shower are electric. Did I just write shower? Yes, the cottage came equipped with a digital Kohler-Mira Magna shower. Of all things (eye-rolling time)!

The first lesson we’ve learned is that having a solar energy system does not mean that once you’ve got it installed, your power expenditure becomes zero. No more utilities bills maybe, but there are still consumables — diesel and propane for back-ups, as well as distilled water to top up the photovoltaic batteries.

Photovoltaic batteries cropt.jpg

Photovoltaic batteries

The second lesson arises from the fact that the generator makes an awful racket. For hours! And the length of time that it goes on to recharge the batteries is totally out of proportion to the amount of time and wattage used. As an example: the first time we used the grill for 30 minutes, the generator ran for over 5 hours! There is noise insulation on the door of the generator room, but the room cannot be totally air-tight as ventilation is necessary. With double-glazed windows closed, the noise is deadened just enough to enable one to sleep (the generator room is in a separate building about 20 meters away). So the lesson learned is staggering the use of appliances. You can use only as much of what you’ve stored in the batteries from the sun. If you use more than is stored at any one time, the generator goes on.

Generator cropped.jpg

Lombardini generator

We’ve learned to use the oven and microwave sparingly and only when there is still sufficient sun to recharge the batteries. Ditto other electrical appliances, such as the vacuum cleaner and washing machine. The refrigerator and freezer are the highest consumers of electricity, being on 24/7. A dishwasher is totally out of the question, said friends nearby who’d already taken out their dishwasher.

The third lesson is that all electrical appliances should preferably be A+++ rated for energy usage, and should not have stand-by lights. Otherwise you realize very quickly that your innocuous-looking vacuum cleaner is an energy hog – even using it for as little as 15 minutes in the afternoon can mean a generator run of several hours in the middle of the night. Not a pleasant experience and certainly not recommended if you’re a light sleeper. Or ultra-sensitive to noise.

The German-made Neff appliances that came with the cottage are rated A+. Even at A++, one can save as much as 50% of the energy used by a non-rated one (according to the Villalonga Town Hall flier on saving energy). A+++ saves even more at 75% — so one can either spend money on the energy savings-rated appliance or on energy consumption. Or add more solar panels and batteries.

We may also decide to replace the current oven with a gas-powered one. And, do without a microwave. Our daughter will be overjoyed, as she considers microwaves unhealthy. The digital shower will also have to go, as it does not function well anyway in a hard-water environment, and in fact has given up the ghost completely. However the stand-by light still keeps blinking, consuming energy! (There is no separate switch for it, alas.) Instead we are getting a simple shower without the bells and whistles, and without all the hassle this has caused us (we were getting alternately scalded and frozen at first). Our washing machine (Miele) is the only appliance we’ve got that is A+++ rated for energy and water usage. It has a 20-minute cycle, no stand-by light, and can use cold water. Even so, I make sure to do all laundry by 2 pm, so that there are still enough hours of sun to charge the batteries.

The fourth lesson is that the conversion of solar energy into electricity is not 100% — it’s more like under 80%, possibly even lower, because of the conversion rate from solar energy to electricity, and the energy diverted to operate the system. Refrigeration apparently consumes 22%, lighting around 7%, the main computer 5%, our laptops 1% each, wifi another 1%. Our light bulbs are mostly energy-saving ones, but we shall be replacing the halogen ceiling bulbs in the kitchen and bathroom with LEDs.

One thing we shall have to do very soon is a proper energy audit: go over the wattage of each appliance, and compare the total with the output capacity of the system. For the winter, when there will surely be rainy and cloudy days with a lot of wind (the Mistral and Levante), a wind turbine may become necessary, as having a noisy generator does not harmonize well with country living. (It’s not only ours, but our neighbours’ as well. But those are at a distance and thus tolerable. Besides we cannot do anything about those.)

And so after one and a half months of living with green power, we are learning that yes, solar energy is indeed great, especially for hot water in the summer. The gas-powered water boiler has not been turned on since the end of May. It is also great to know that we are contributing, albeit in a very small way, to reducing grid-electricity consumption and carbon dioxide emissions.

We have learned that this system does not entirely eliminate dependence on fossil fuels; it only reduces consumption. And having to monitor our energy usage makes us fully aware of precisely how much fossil fuels we consume, even with solar panels. Additionally, there is the issue of environmental pollutants emitted by the diesel generator. Most certainly we shall have to learn a more judicious way of using this self-generated energy. And quite possibly, consider a different company to maintain the system. Certainly not one that tries to excuse its failure to come when it was supposed to, by lying about it, saying they called three times, and there was no answer. (We were home the entire time indoors as it was a very hot day, so they were telling porkies.) But… this is, after all, the land of mañana. The mañana I don’t mind. Not very much anyhow. The lying I most definitely do.



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