Monthly Archives: February 2011

Seawater Greenhouses

For those who’ve come to my talks and classes you’ll know that I’m a passionate advocate of Seawater Greenhouses, yet this is the first time I’ve written about them on this blog. They are one of the game-changing technologies that form part of the interconnected web of solutions to our global web of problems: Climate Change, Ocean Acidification, Peak Oil, Hunger, Poverty, Loss of biodiversity, Soil Erosion, Water Shortage etc.
The Seawater Greenhouse offers one of the most revolutionary and hopeful technological innovations for ecologically restorative agriculture in the hot arid zones of the world, especially those near the coast. The Seawater Greenhouse process is relatively straightforward: seawater is poured down a cardboard lattice at one end of a plastic greenhouse, while hot dry desert air is blown through the lattice, evaporating the water and leaving the salt behind on the lattice. The now cool moist air makes an excellent growing environment within the greenhouse. Before this moist air leaves the greenhouse it hits the cold surface of plastic pipes filled with flowing cold deep-seawater, where the vapour condenses. The amount of fresh water created in this way is greater than that needed to irrigate the crops growing in the greenhouse, leaving a surplus for irrigating outside orchards or supplying local communities with fresh water.
Charlie Paton thought-up the idea in 1991 and the first trial project was built in Tenerife in 1992. The concept was proved to work and two further research greenhouses were built, one in Abu Dhabi in 2000 and then one in Oman in 2004. The first commercial horticultural seawater greenhouse project has been built near Port Augusta in South Australia and produced its first crop of tomatoes a couple of months ago.
Seawater Greenhouses and Concentrating Solar Power will have synergistic benefits when developed together, and offer the scope for further beneficial uses of the water and electricity so created; surplus water can be used to grow trees and crops outside the greenhouses, develop algae biofuels and aquaculture, sell electricity, horticultural produce and possibly a wide range of other produce including algal bio-fuels. Charlie Paton and his colleagues have researched the possibility of this wider integrated development for some time and use the term “The Sahara Forest Project” to describe this process, which could of course be adapted to a wide variety of desert locations. It has just been announced that the first of these larger scale integrated developments is to be built in southern Jordan, near the port of Aqaba. At this time of political flux in North Africa and the Middle East this is just the kind of ecologically restorative project that offers the hope of sustainable prosperity for the people of the region. I wish this project well, and will follow developments on this blog.

For more see

In with the New Solar Age

As I write the situation in Egypt and more generally across the Arab world is in flux, sparked by the ease with which Tunisian protesters ousted Ben Ali. Thousands of protesters are out on the streets calling for old despotic leaders to step down and for a democratic process to begin and everywhere people want an end to corruption and stifled economic opportunities. Youth unemployment is very high across the Arab world, and people want jobs and the chance to make a better life for themselves.
North Africa and the Middle East is also one of the key areas of the world in which the transition from “The Fossil-fuel Age” to “The Solar Age” is beginning to unfold. On 23rd December 2010 Egypt opened the Kuraymat power station (see a 150 MW hybrid, 20MW of solar thermal pre-heating of steam entering a gas fired power station, very similar to ones opening around the same time at Ain Beni Mathar in Morocco and at Hassi R’mel in Algeria. These are all relatively small scale in terms of solar, but hugely significant as the first solar power stations in North Africa.
( Kuraymat power station)
In November 2009 the Moroccan government announced its Solar Plan and the founding of Masen, the Moroccan Agency for Solar Energy, to facilitate the plan. The aim is to have 2,000 MW of solar power stations up and running by 2020. This would represent 38% of installed capacity at that time. However many countries are finding that once they start installing renewables they exceed their own plans in no time: China met its wind power goal for 2020 already in 2010, a full decade ahead of schedule, and Morocco may possibly do likewise with solar.
For those of us concerned about Climate Change and giving people better democratic and economic opportunities these are critical times. While the unrest persists there is likely to be a cautious approach to investment (see, and thus establishing a peaceful transition is important for jobs in the solar industry to be created. I wish the protesters well, and hope that they can bring about a peaceful transition to democracy, and that these new governments are even keener than their predecessors to develop the solar powered economies that are their best chance of sustainable prosperity.
There’s an interesting youtube clip on the new Moroccan solar/gas hybrid plant here