Carbon Copy

hydrogen economy is more hype than substance

I have said before that hydrogen's usefulness is more as a storage medium than as a source of energy in its own right. But here's a well-referenced assessment of the science by Alice Friedemann, suggesting it isn't of any value even for storage:

The laws of physics mean the hydrogen economy will always be an energy sink. Hydrogen’s properties require you to spend more energy than you can earn, because in order to do so you must overcome waters’ hydrogen-oxygen bond, move heavy cars, prevent leaks and brittle metals, and transport hydrogen to the destination. It doesn’t matter if all of these problems are solved, or how much money is spent. You will use more energy to create, store, and transport hydrogen than you will ever get out of it.

And the conclusion? The energy and environmental challenges facing the world are far too serious to spend effort on dead-end technologies. Policy needs to guide investment based on a firm grasp of both science and geopolitical realities. The risk is that lobby groups will sway government to create misguided incentives, such as the US corn subsidies aimed at ethanol production.

algal biofuels: the next wave

Using a third-generation biofuels technique to create ethanol from algae in seawater, one company claims it "will be the largest consumer of CO2 on the planet". Algenol Biofuels says it will be able to create 100 million gallons of ethanol from 1.5 million tons of CO2 at a facility in Mexico, with a yield of 6,000 gallons per acre per year. In comparison, corn yields only 360 gallons per acre per year, and sugarcane 890 gallons. Expecting to be producing at scale by the end of next year, the company hopes to produce "the cheapest fuel on the planet".

energy standards for buildings jacked up in SA

The South African Bureau of Standards (SABS) will soon be releasing SANS 204 to set new standards for energy efficiency in buildings. If implemented following the public comment period, this should raise the bar for reduced energy consumption from air conditioning and heating. It's not clear how this would be implemented, given the shortage of energy auditors, but SANS 204 and the forthcoming release of the Green Star building rating system by the Green Building Council of South Africa should create greater impetus for the establishment of an industry of consultants and contractors who understand energy efficiency.

schooling fine young greenies

German firm Schucco has developed a solar project at the Deutsche International Schule in Johannesburg. PV modules generating 3.48 kW, together with a solar water heating system, are expected to save the school 22,300 kWh of electricity a year, cutting emissions by 18,000 kg a year. That's great, but what I find hard to believe is the claim that the payback period for a similar system on an industrial scale would be less than a year. If that were true, we'd all be rushing out to install these systems. Do the Germans know something we don't?

microgeneration could rival nuclear power

One in five buildings in Britain could become mini power stations, with the right incentives in place, according to a new report commissioned by the UK Department for Business, Energy and Regulatory Reform (DBERR). A large-scale shift to microrenewable energy could save 30m tonnes of CO2, equivalent to 5% of all UK electricity. Such widespread microgeneration would need a feed-in tariff scheme so that homeowners could sell electricity to the grid, and there would need to be some combination of grants, subsidies and soft loans. But this investment by government would be partially offset by effectively outsourcing the project management costs and effort required for large-scale projects, by putting the initiative in the hands of individuals. This "distributed project" would reduce investment needed in more traditional generation facilities. On top of that, job creation would be more widespread.

another way to use biomass

Just to prove that biomass as a fuel isn't just about gathering sticks to cook supper on, Britain's largest power station has launched a project to replace 10% of the coal it uses with materials such as wood chips, sunflower husks or grasses. That's equivalent to 400 MW of power generation, or the output of 500 wind turbines. The station, Drax, produces 7% of Britain's electricity, and has tested injecting powdered biomass into coal-fired boilers.

Neil Crumpton, of Friends of the Earth, said using biomass in power stations or combined heat and power schemes was a better use of the resource than turning it into biofuels. "Co-firing with biomass is a reasonable way forward; it's a logical extension of what they're [Drax] already doing and I've got no qualms about it. If it helps build the sustainable biomass market in the UK, then all well and good."

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.

green giants

Forbes has "surveyed the clean energy landscape for new and recently completed projects in solar, wind, geothermal and wave energy that produced the most grid-connected electricity", producing a list and photos of the world's biggest clean energy projects.

storing heat underground

Some innovative green buildings use piles of rocks in the basement to store heat or coolness, to even out the night and day temperature fluctuations in buildings without air conditioning or fossil-fueled heating.

Now, tests have shown that it is feasible to store heat underground to do the same thing over several months instead of just days, using what amounts to sub-surface radiators. Paving on roads and parking lots do a wonderful job of storing the sun's heat. In summer, this unfortunately contributes to the urban heat island effect, but where pavement is necessary, the heat could be harvested in summer to keep ice off roads in winter, or to heat buildings.

In the UK, scientists found in a trial on a section of road that enough heat was captured in the summer of 2006 to keep the road above freezing for almost all of the following winter. On average, the heated surface was 3C warmer than the surrounding ground. And a trial at an Edinburgh supermarket car park suggested that the system could cut the store's carbon footprint by 70% and slash annual fuel bills by £26,000 for an initial investment of about £180,000.

wanna move some dirt?

Everyone knows about hybrid cars, but unless you are into heavy machinery, you probably haven't heard of the new hybrid Caterpillar D7E dozer. From next year we'll start seeing it on construction sites. A bit like a diesel-electric train, this Cat uses a diesel engine to generate electricity, which feeds electric drive and steering motors. It will be able to move 25 percent more material per gallon of fuel than the machine it replaces. Less fuel means less emissions, so this baby will help reduce the carbon impact of big construction projects.