Why so thirsty? Because power plants need a lot of cooling water. To absorb waste heat, many of the nation’s aging fossil fuel and nuclear power plants rely on a ready supply of cool water from rivers, lakes or estuaries. Older plants in particular rely on outdated cooling technology that needlessly sucks in and kills fish and other aquatic life and discharges water at a far higher temperature than when it entered the plant.

State and federal regulators have recently tried to rein in this destructive process, but the power industry has been strongly reluctant to upgrade its cooling equipment. So if damaging entire aquatic ecosystems isn’t a good enough reason to get on board with 21st century technology, how about the risk to electric reliability and the industry’s bottom line? What if that unquenchable thirst for water resulted in power plants having to scale back their power production, or even shutting down completely because of a lack of cooling water?

Wouldn’t that be unbelievable?!

Actually it wouldn’t, because it’s already happening. Power plants that were planned and constructed decades ago now face changing rainfall patterns and unusual temperature swings, sometimes causing them to shut down their turbines and wait for wetter and/or cooler days. The Union of Concerned Scientists (UCS) released a report recently that pulls together many different examples of such water-related scenarios already challenging the power industry, whether it’s ready for an increasingly water-constrained world or not.

Here’s a brief summary of UCS’s regional breakdown:

Northwest: Relying on hydropower to provide 60 percent of its electricity generation means the Northwest is particularly susceptible to shifting rain, snowpack and runoff patterns. The change in streamflow of the region’s mighty rivers, which could get more dramatic with climate change, can pose big problems for hydropower generation, electricity pricing and fisheries.

Great Plains: The Great Plains Aquifer is being depleted, yet power plants and other users continue to fight for an increasing share of the dwindling supply. A recent drought caused a Wyoming coal plant to tap into the aquifer for its cooling water, in a direct collision with the region’s irrigation needs.

Southwest: The region where you’re likely aware of headline-making water crises, and where an increasing population and its water demands are meeting head-on with severe water constraints. The region’s power plants are more water efficient than most, but still have their needs, and large hydropower facilities are facing record-low reservoir levels.

Midwest: A growing demand for electricity generated by water-intensive coal and nuclear power plants is combining with a growth in population and agricultural demand. During a summer heat wave in 2006, for example, several plants had to reduce power production by up to half because water temperatures were too warm to cool the plants.

Northeast: The region’s nuclear power plants — as well as its fossil-fueled plants — have caused tremendous damage to aquatic ecosystems. Recently many of those plants have begun to face regulatory pressure to end their destructive habits. Some are innovating and reducing their water dependence, like the Kendall Station in Massachusetts , while others continue to resist and expose themselves to future water risks.

Southeast: Two-thirds of freshwater withdrawn in the region goes towards cooling power plants. Recent hot and drought-ridden summers have left water-dependent power plants with either too little water for cooling or with water too warm to efficiently cool the plants. The result is less electricity production exactly when the region’s energy needs are highest.

The water demands of the nation’s current energy infrastructure are increasingly running into conflicts with other uses. In the Southeast, for example, Lake Lanier’s drought-susceptible supply is vital for Atlanta metro area residents, the marine life of Florida’s Apalachicola River and Bay, and for cooling a nuclear power plant that powers much of Alabama. In such a case, why wouldn’t the power industry want to reduce its exposure to risk and rely less on an overtaxed water supply?

So what doesn’t require water for cooling? Air-cooling for power plants is water-free, although comes at a higher cost and requires a relatively small amount of additional power to operate.

Wind and solar photovoltaics require no water to generate electricity. Conserving energy and becoming more energy efficient doesn’t require a drop.

As the UCS report concludes:

The choice is simple: continue with business as usual and hope we avoid energy-water collisions (and the costs associated with them), or build a water-smart energy system that can provide us with energy security while protecting our precious water supplies.

Some power plant owners have made valuable upgrades to their cooling systems and operations, or have begun to invest in far less water-intensive renewable energy sources, but sadly this is the exception, not the rule. The choice may be simple, but so far, most of the industry continues to ignore its obvious water problem.

Source: ecocentric

Although the above article cites examples in the USA, a similar situation is occurring worldwide, including South Africa where water scarcity is far more serious.  Solar and wind energy need to be developed in South Africa, especially solar energy with our high irradiation rates.

Speak to Water Rhapsody for your free quote today.

If South Africa wishes to become a country that encourages scientific development, it would be in the countries best interest to invest in technologies of the future, like photo-voltaic energy and a telescope that would allow us to see further out into the universe. South Africa shares a unique disposition with few other countries where sunshine predominates our climate. This lends these countries to be ideal photo-voltaic energy catchment hubs, hubs that could power even developing nations.

Oil giant Shell’s plans to prospect for shale gas in the Karoo could affect South Africa’s bid to build the world’s biggest radio telescope.

This 1,000ft telescope is the largest curved focusing dish on Earth and is sunk in a limestone basin in Puerto Rico.

They were asking how such exploration might impact on the Square Kilometre Array (SKA), he told Parliament’s science and technology portfolio committee.

South Africa and Australia were shortlisted in 2006 as locations for the SKA project.

The SKA will cost about two billion euro to build, and require between 150-million and 200-million euro a year, for 50 years, to maintain and operate.

The radio telescope – brainchild of a consortium of major international science funding agencies in 16 countries – comprises 3000 giant antenna dishes, each the height of a three-storey building.

Astronomers plan to use the SKA to peer back through time, across vast distances, to investigate the history of the universe and when the first stars were formed.

The SKA core site in South Africa is near Carnarvon in the Northern Cape, where many of the dishes would be erected.

The plan also includes locating receiving stations, each comprising about 30 antenna dishes, in eight other African countries, some as far away as Ghana and Madagascar.

An announcement on who has won the bid will be made early next year.

Munsami said on Wednesday questions about Shell’s plans were starting to “creep in” to South Africa’s international lobbying strategy.

“Obviously, from a SKA perspective, we are concerned about it… In terms of the international lobbying strategy, it’s starting to creep in as well; the international partners are starting to ask where this is going and how it will impact the SKA.”

The department was looking at the implications of the oil company going ahead with its exploration for shale gas.

“One key piece of legislation we have in place is the Astronomy Geographic Advantage Act, which regulates the area in terms of radio interference,” Munsami told the committee.

“Obviously we will be looking at whether, in terms of exploration, there is any radio interference. If there is, we will have to have that discussion in terms of the regulatory framework.”

A management authority was being put in place within the department to deal with the matter, and “to ensure regulations are fulfilled in terms of protecting the SKA”.

There was also “ongoing” discussion between his department and the department of energy on the matter, Munsami said.

Committee chairman Nqaba Ngcobo noted the Astronomy Geographic Advantage Act gave the sole right to regulate the zone in which the SKA would operate to the minister of science and technology.

“So I think that’s not a problem… There is no way Shell can go ahead with that; the Act does not allow it. It can’t,” he assured members.

Anita Loots, associate director of South Africa’s SKA team, said a key issue was that nothing untoward happened while radio frequency interference (RFI) tests were being conducted in the Karoo.

A team from the international SKA technical committee is currently in the country to carry out such RFI tests. Similar tests are being conducted in Australia.

The team’s report will contribute towards determining which of the two countries win the bid.

“The key issue for us is that while the RFI measuring campaign is going on in South Africa and Australia, that there is nothing happening in the Karoo that requires people to carry a cellphone, or some sort or radio transmitting equipment, or whatever can actually impact on that measurement,” Loots said.

“Because… although the fracking may happen quite a bit later, the immediate effect of it is if there are very strong radio signals in that area because of the exploration.”

The “fracking” referred to is hydraulic fracturing, a technique for extracting shale gas from deep underground by pumping a pressurised mixture of water, sand and chemicals down drill holes.

- Sapa

Deputy Director-General of nuclear and clean energy Ompie Aphane told the national council of provinces’ select committee on economic development that the suspicion of collusion arose because the local capital cost of the solar geysers was far higher than the imported price inclusive of duties. Also, the prices of systems escalated sharply by about 40% shortly after Eskom introduced its rebate. “There is something that is not adding up,” Mr Aphane said.

Also, the fact that there was a restricted group of accredited suppliers dampened competition. He noted that by the end of this financial year only 55 000 solar water geysers would have been installed nationwide since the programme was launched- far off the one million target for 2013 and the 5 to 7 million target by 2019.

The almost doubling of electricity tariffs over the next few years was expected to accelerate the demand for solar water systems.

Source: Business Day

Mimicking nature

Researchers at North Carolina State University, United States, have shown that water-gel-based solar devices, or “artificial leaves”, can act like solar cells to produce electricity. These leaves are bendable devices composed of a water-based gel infused with light-sensitive molecules, which are then coupled with electrodes coated in carbon nanotubes or graphite. The team’s findings prove the concept for making solar cells that more closely mimic nature. These devices also have the potential to be less expensive and more environmentally friendly than the standard silicon-based solar cells.

According to Orlin Velev, a professor of chemical and biomolecular engineering, “[W]e do not want to overpromise at this stage, as the devices are still of relatively low efficiency and there is a long way to go before this can become a practical technology. However, we believe that the concept of biologically inspired ‘soft’ devices for generating electricity may in the future provide an alternative for the present-day solid-state technologies.” Velev says the team now plans to fine-tune the photovoltaic devices to make them even more like real leaves.

Source:NCSUnewsroom

• Of the top-25 highest CO2 emitting power generating plants worldwide, South Africa has three stations.
• South Africa is number eight of the top 50 countries with the highest CO2 emitting power sectors.
• I have no figures for South Africa, but in the US of A 67% of the sulphur dioxide emissions are from power generation.  Just in case the minister has not had any chemistry lessons, sulphur dioxide does not sound so terribly bad if you say these quickly.  SO2 (sulphur dioxide) when mixed with water forms H2SO4 (Sulphuric acid).  This stuff is what acid rain contains.
• In April this year the World Bank approved a loan of three thousand seven hundred and fifty million Dollars ($3.75 billion) to build a dirty coal fired power station at Medupi.
• At the same time the World Bank approved a loan of a mere $260 million for wind and solar power.
• After Kisile and Medupi come on line 94% of all electricity generated in South Africa will be generated by coal fired power stations.  The sum total of all the coal fired power stations in South Africa will deliver a cumulative emission into the atmosphere of:
• Sulphur dioxide, SO2 3 360 000 tons
• NOx  3 400 000 tons
• Carbon Dioxide CO2 1 243 000 000 tons
• Particulate matter: 168000 tons
• Hydrocarbons: 73920 tons.
• CO: (carbon Monoxide) 241900 tons
• Ash: 42 000 000 tons
• Sludge: 64 800 000 tons.
• Arsenic:  34 tons.
• Lead:  17 tons
• Cadmium:     600 kilograms.
• Uranium and many other toxic metals.

The largest water users

It is useful for our honourable minister to know that wind generation produces none of the toxic substances at all, and no water as well, whereas, coal fired power stations use 1.32 litres of water per kilowatt hour of electricity generated.  The sum total of water required for all of the power stations is six times the equivalent volume of the Vaal dam.  This makes Eskom the biggest single consumer of water in country.

The quantity of tons of stuff that will exit South African power stations is so huge that it is beyond imagination.   I wish therefore to provide the honourable minister an analogy:  if the sum total of all the toxic substances listed here, emanating from all of the coal powered stations in South Africa, were to be placed into one ton vehicles nose to tail, these would stretch around the world at the equator 212 times every year.

1. Educate to change consumption and lifestyles
In the end, changing the face of this crisis involves education to motivate new behaviors. Coping with the coming era of water scarcity will require major overhaul of all forms of consumption, from individual use to corporates. Some regions led by India, Australia and the Southwest U.S., are already facing the freshwater crisis. The most critical task is making sure the problem is much better understood worldwide.

2. Invent new water conservation technologies
In areas where aquifers are drying up and rainwater is increasingly unpredictable, innovation is needed. But as we attempt to cope with freshwater scarcity and develop conservation technologies, energy consumption is an important consideration.

3. Recycle wastewater (Greywater recycling)
In March, World Water Day panelists urged a new mindset for wastewater treatment. Some countries, like Singapore, are trying to recycle to cut water imports and become more self-sufficient. The rich East Asian republic is a leader in developing advanced technology that cleanses wastewater for other uses, including drinking.

4. Improve irrigation and agricultural practices
Some 70 percent of the world’s freshwater is used for agriculture. Improving irrigation can help close supply and demand gaps. In certain cases profligate irrigation practices meant for an earlier era has weakened the ability of farmers to provide food and fiber to a growing world.

5. Appropriately price water
Water pricing and rights go hand in hand, with consumers questioning the benefit of higher prices. According to experts from the Organization for Economic Co-operation and Development (OECD), an international economic forum of 31 of the world’s richest countries, raising prices will help lower waste and pollution.

Fuel Cell

The power output is small, orders of magnitude lower than from hydrogen or methanol fuel cells, but the supply and handling of these flammable fuels is avoided. It is proposed that the cell might be used in applications which require relatively low power consumption, for example sensors of various kinds or emergency signaling units, and that the devices might be used best in desert or warm coastal regions where the water is readily evaporated from the cell, thus maintaining its concentration gradient.

Source: Forbes blog