going solar at home

OK, it's been how many years? I bought a cordless electric lawn mower back in 2004 with the idea of gradually replacing most of my electrical tools with cordless ones so that they could be charged from solar panels.

I have now finally splashed out and bought my first solar pv panel, battery, regulator and inverter. The lawnmower is no longer running - just needs a new battery, I think - but now I can start weaning myself off the grid.

The catalyst for getting the panel was a trip to the AfrikaBurn festival in the Karoo, where there is no power, no water and no cellular phone reception. In fact nothing at all. Thousands of people descend on the temporary Tankwa Town in the desert, and a week later they pack up and leave nothing behind. It's the little brother of Burning Man in Nevada, USA.

As it turns out, I am getting a ride to AfrikaBurn with a colleague, as my car has needed emergency repairs, so I can no longer bring the solar equipment. But at least I've made the initial leap. Here's what I bought (and if you're in Cape Town, I recommend SetSolar as a supplier):

90W panel manufactured right here in Cape Town by SetSolar (model M750P)

• Steca 6.6F - 6A charge controller 12/24V
• One 100Ah deep cycle battery 12V
• Cotek 350W pure sine wave inverter 12V

Total bill: R5,700 (about USD 850)

That's not big enough to run more than a typical desktop computer for more than three hours when the sun's not shining, but it's easy enough to add batteries and panels as the cash becomes available. But my initial purpose is to run a small water pump for a grey water system I hope to build. I will keep you posted on that too.

sweat the small stuff

All those gadgets add up. It's not just refrigerators and air conditioners and electric heaters we need to worry about in our homes. The International Energy Agency estimates that worldwide, consumer electronics now represent 15 percent of household power demand, and that is expected to triple over the next two decades. Any gains made in the efficiency of electronic appliances have been offset by increasing numbers, and by the increasing tendency for devices to be 'always on'. To satisfy the demand from gadgets will require building the equivalent of 560 coal-fired power plants, or 230 nuclear plants, according to the agency.

cordless lawnmower in SA

When I was living in Ontario five years ago, I bought a cordless lawnmower. But I haven't seen one here in South Africa - until now. The Brio cordless electric 500 Rotary Lawn Mower is available from BesTech Outdoor for just under R4,000. They have other cordless garden tools too. Since most of South Africa's electricity is produced from coal, this is not emission-free gardening - but the emissions from the coal-generated electricity used by the mower is far less than what spews out of petrol-driven lawn mowers, and if you charge it with solar panels or a wind turbine, then the benefit is multiplied.

Of course it would be better if we just had less grass, but until everyone converts their gardens to mini urban farms, or indigenous gardens, this is the next best thing for reducing environmental impact - a compromise not unlike buying a hybrid car.

changing the world, one switch at a time

Most technological innovations that aim to reduce carbon emissions do it either by switching to renewable energy sources (Strategy One), or by increasing the energy efficiency of the technology (Strategy Two). A third strategy is to eliminate or reduce the use of the technology altogether.

So, for example: to reduce emissions from lighting, you could install photovoltaic panels (Strategy One), switch to LED lights (Strategy Two), or design a house to provide more natural light (Strategy Three). Or for transport: switch to an electric motor and charge the batteries using green energy (Strategy One), reduce the weight of the car and use a more efficient propulsion system (Strategy Two), or make it easier to walk or cycle by providing safe and convenient routes for pedestrians and cyclists (Strategy Three).

In most cases, the third strategy is the most effective at reducing emissions, but also the most difficult to achieve. This is partly because it often requires coordinated planning on a level that is rarely achieved. In the transport case, urban planners, transport engineers and others need to put their heads together, and in the lighting case architects and building engineers need to do the same. Just as difficult is the behaviour change that is required by the users - people who need to travel, or people who buy and occupy buildings. There is immense resistance to change, and some would argue that inducing change in a certain direction can have unintended consequences, or not be effective at all. (Think of ethanol from corn, encouraged by subsidies in the US.)

Here's an idea for Strategy Three that, for all I know, could have some unintended consequence; but what I like about it is its simplicity and ease of implementation. The SmartSwitch is like having someone tell you not to turn on the lights unneccessarily:

SmartSwitch doesn't restrict the user from turning on a light, but rather it passively encourages behavior change. SmartSwitches can be programmed to respond to either personal or communal electrical usage. In a home wired with SmartSwitches, lights can become harder to turn on during hours of peak demand. The switches can also be customized to reflect household-specific energy conservation goals.

outmoding the commode

What the modern fridge does for household electricity consumption, the modern toilet does for water. Actually, the toilet - in its most common form - is not modern at all, and it's time for a makeover. But toilets that use little or no water face the same problem I mentioned yesterday in relation to the energy-efficient refrigerator: poor public image. I am not talking about the low-flow models that are now fairly common in some countries. Five- or six-litre flush toilets are a bit like the hybrid car: better than gas-guzzling 4x4 vehicles, but not something that will really wean us off liquid fuels.

I am talking about a litre or less per flush. We need a revolution in the water closet, and Dwell magazine presents a few models that might do the trick. But they are a long way from price levels that will encourage widespread adoption, and some of them still look like they belong in a caravan, not a house. Design, design, design.

old fridge design brought back to life

A few years ago, when I witnessed the effects of Eskom's budget-sapping rollout of the national electricity grid to rural Transkei, I wondered how people who rely on a largely subsistence economy could possibly afford to buy, operate and maintain the electrical appliances that they could now run on 220 volts of coal-generated power. Most rural families probably have one or more family members working in cities, sending money back home, which helps pay the bills; but is that really a sustainable approach to community development?

I have written before about alternative financing models for supplying renewable energy to make rural life more convenient, and here is another technology that could help significantly: a fridge design that was invented by Albert Einstein in 1930. The original design was abandoned when freon and cheap power made it possible to sell fridges that operated with more efficient compressors. But the compressor is what makes it difficult to run a modern fridge using solar power, so the Einstein fridge is being dusted off and improved so that its zero-moving-parts design can be powered with solar panels. In addition to reducing reliance on dirty power, this approach also reduces maintenance needs, so it's perfect for rural communities.

Of course there are more primitive systems, like evaporative fridges, but let's face reality: a huge challenge in stemming the tide of human desire for electrically-powered appliances in the developing world is in coming up with designs that don't make people feel like they are being handed second-rate goods. This sounds like one that could work.

for men only

You may have heard of waterless urinals, and at least one manufacturer is making the lowly urinal even greener. Soybean urinals from Waterless Co. are made from approximately 30 percent soybean resin, which is a naturally sustainable resource.

the future of LED lighting

Here's an article reminding us that the uptake of new technology is not just about the technology itself. Some people see LEDs as the future, with CFLs as an intermediate technology that will soon be replaced. Others suggest that even the old incandescent bulb will never completely disappear. We still use candles, don't we? Everything seems to have its place, but whether through market forces or regulation, some things will be discouraged. The question is what? and how?

the future is light

It's still a real challenge to find product suppliers who understand what products are suitable for solar energy. There's lots of general information on the internet, but what I need is local knowledge of what is available right here, in my city. I've been combing the local shops for LED lights. There are lots of LED downlighters, but even at Eagle Electric, one of Cape Town's biggest lighting suppliers, the shop assistants are clueless about how much light you get per watt of electricity consumed. I need to understand how many LED lights are needed for general lighting or for specific tasks, to replace traditional incandescent or new CFL lights, and this depends on the particular product. Not all LED lights are created equal.

So this morning I had an 'aha' moment when I read in the Cape Times 'Techno Times' supplement about LEDlighting, a Cape Town company that designs commercial LED installations and gives advice on energy-efficient lighting. If you need LEDs, Pierre van Helden is your man. The company doesn't have a retail outlet, but if you want to transform your house to reduce your carbon footprint, give him a call.

In the TechnoTimes reproduction of a Popular Mechanics article, Pierre suggests that LEDs will change the way we see lighting. Instead of an easy-to-replace central bulb in every room of the house, distributed lighting will become the norm, with fixtures embedded into furniture or other elements of the room. Since they can last up to 20 years, LEDs don't need to be easily accessible. Design options are more flexible, and clever design is more important for energy efficiency. We don't need uniformly bright light, but rather a lower level of ambient light with additional task-specific areas of light.

tech, tech and more tech

Another attempt at predicting what features might be in the house of the future. Am I the only one who wonders why the future is always portrayed as "current trends, amplified"? I have seen pictures from old magazines envisioning cities of the future with skyscrapers that dedicated most of their space to allowing cars to drive to the top, to meet airplanes landing on the roof. The dreamers were enthralled at the prospect of moving up to previously unimagined heights, but failed to consider that cars were not the way to get there. If there is one thing forecasters have been notoriously bad at, it's anticipating how new technologies will be used - invariably there are unintended behaviours and designs that result.

Still, one thing that most certainly will be needed in houses in the very near future is improved monitoring of resource consumption. Today's carbon calculators are too simplified and generic to be much use in tracking attainment of personal, municipal and national targets. We need to be far more aware of the impacts of individual day-to-day decisions.

One of the ideas expressed at the Green Building Retrofitting Seminar on 10 April was "sweat the small stuff". We can't rely only on grand plans to manage resources more responsibly. Colin Devenish from the V&A Waterfront in Cape Town pointed out that if toilets were modified to reduce water consumption by only one litre per flush, the Waterfront would save 23 million litres a year. But we can't manage what we don't measure.