manure to gas

Ethanol production normally uses natural gas or coal as the energy source to distil ethanol from plants, and requires the input of one British thermal unit (btu) to make 2 to 2.5 btus of ethanol. Here's another method that only needs 1 btu of energy input to produce 46 btus of ethanol:

Stand cattle on slatted floors, gather the dung, extract methane and use the methane to to power an ethanol plant. By-products include fertiliser for the surrounding maize fields, and wet distiller's grain. Some of the maize is used to feed the cattle (with the distiller's grain) and the rest is distilled into ethanol.

This closed-loop system is being piloted in the Genesis project in Nebraska, where water is also being recycled.

where are renewables now - really?

According to the International Energy Agency (IEA), renewable energies met 13.2 percent of world primary energy demand in 2004. From the perspective of weaning ourselves off fossil fuels, that's a low base; but it's higher than I would have thought. The problem lies in how we define "renewable", because most of this is biomass: firewood burnt by billions of people in the Third World.

Technically, firewood is renewable; but practically, it is often a diminishing resource and a health hazard, and chopping down trees can devastate the local environment. (There are exceptions, such as in parts of South Africa where alien vegetation is chopped down and sold as firewood to restore biodiversity, improve groundwater supplies, and create jobs.)

Renewables are key to tackling climate change and energy security because we need to tackle the challenges on many fronts. But - and this is especially important if we want to avoid a proliferation of nuclear power stations - a report by the National Renewable Energy Laboratory (Tackling Climate Change in the US) shows that energy efficiency will do more to offset emissions than all available renewable energies combined. (The focus of the report is potential carbon emissions reductions from the use of geothermal power.)

sigh of relief

Did I hear right? Have US federal politicians actually agreed that human-induced climate change is beyond doubt?

sinking to the depths

It seems the oceans as a carbon sink may play a bigger role in mitigating CO2 emissions than previously thought. If true, that would help counter global warming, but at what cost to marine life? The changing ocean chemistry may, for example, affect deep-sea corals and shelled organisms.

low-energy house design

Two things I really like about this off-grid house in Alberta: First, it's setting a good example in a suburban area, where it counts the most; and second, the fridge is next to a cold closet vented to the outdoors, which allows the fridge to be turned off in winter. This article outlines the principles of low-energy house design, without the technical detail. It's ten years old, but still a good overview.

Update on 27 February 2007: And in a completely different climate, there's a cob house in Cape Town that's being built right now, encompassing a range of sustainable design features. And it's urban. Yeah!

first hiccup in SA biofuels strategy

The South African Department of Minerals and Energy may use genetically modified canola for producing biofuels, which would be used with Roundup herbicide produced by Monsanto. There are plans to plant 70,000 ha near East London and process it at a nearby biofuels plant for export to the EU. According to a report in the Cape Times today, a representative of the NGO Third World Investment Gateway is concerned that farmers who start the programme would not be able to switch later to crops that are not "Roundup ready". Reports from the WHO show that Roundup remains in the soil, and could prevent growth of other crops.

Several studies have pinpointed Roundup as an endrocrinic disrupter, affecting hormonal balance and immune systems, with offspring being especially vulnerable.

slowing desertification

The march of the Sahara has been slowed in Niger by a change in government policy, and the response of farmers to this policy. Apparently with no investment money, the desert is being reclaimed as farmers nurture saplings that they once chopped down for fuel, because the farmers now own the trees on their land, giving them an incentive to treat them as a resource more valuable than their use as woodfuel. They now sell fruits, pods, bark and branches at a level that sustains the growing forest, with the additional benefit that the topsoil is not blown away and other crops survive alongside the trees.

It is also reported that the water table is higher now, but it is not clear whether this is simply a result of better rainfall. In some countries, alien trees are being eradicated partly because they are big consumers of groundwater, but that seems not to be a concern in this case. According to a comment on an article on WorldChanging, these trees in Niger are acacias, which are legumes, fixing nitrogen in the soil and improving it.

diversifying the energy mix in SA

South Africa's Western Cape Integrated Energy Strategy, launched January 2007, reports that the province produces 30.5 million tons of CO2 emissions a year from energy consumption. Twenty-two percent of this comes from the transport sector, which consumes 34% of the energy used in the province. The country's biofuels strategy will help lessen transport's reliance on fossil fuels - though it will do almost nothing to reduce emissions.

Emissions from industry, which consumes 48% of the Western Cape's energy, is being addressed through a strategy to diverisfy the energy mix. The current mix for electricity in the province is 50% from nuclear and 50% from coal. The Integrated Energy Strategy aims for 15% of electricity to be generated from renewable sources. The province seems to recognize the need for demand-side management, but there is no target or strategy in place for reducing consumption or improving efficiency.

[Source: Cape Argus, 15 February 2007]

the bell tolls

People are willing to adopt the "pay-as-you-go" model for all kinds of services and infrastructure, from the telephone to parking lots. But for using roads? Political opposition to road tolls is strong in many countries, but commentators are starting to think that a begrudging acceptance of congestion pricing in some quarters may indicate acceptance - finally - that it's futile to try to keep building our way out of gridlock.

Washington has allocated funds to help states and cities develop congestion pricing systems, and may even apply the same concept to airlines: charge users more to travel in congested corridors, encouraging them to change their route or time of travel.

interstitial living

Two ideas on infilling using Toronto's neglected spaces.

One: Using alleyways for creative architecture is surely a positive thing, but it seems unfortunate that developers have to resort to the OMB to make it happen. When will city Works Committee kiss and make up with the planning department?

Two: The elevated Gardiner Expressway cuts a swath between the CBD and the Harbourfront, creating a wasteland beneath and an eyesore above. Many people would like to see it torn down, but the approach so far has been to try and reclaim the shadowlands for other uses - a bit like the Cape Town International Convention Centre has done with part of the foreshore freeway.