How offshore wind turbines could be more efficient

phys.org
17 Aug 2012

As wind farms are increasingly sited offshore rather than on land, and installed at water depths of up to 40 metres, a Cambridge University engineer is urging the wind power industry to look again at the design of the heavy supporting towers and foundations used out at sea in order to improve the energy payback achieved.

Jim Platts of the Institute for Manufacturing (IfM) believes that the wind power sector could achieve significantly higher payback ratios if turbine manufacturers used guyed towers (towers held in place by steel cables) made in composite materials rather than free-standing towers made in conventional steel materials.

A preliminary study undertaken at IfM suggests that payback ratios for offshore wind farms could be doubled if the industry embraced new construction methods.

"The development of the wind turbine industry, and the way in which it works with the civil engineers who make the heavy supporting towers and foundations, which are not visible out at sea once the turbines are installed, mean that we have ignored something which is almost embarrassingly obvious in our race to meet the targets set for renewable energy production", said Platts.

"We urgently need to reduce the high levels of energy embedded in offshore wind turbines which make them both ineffective in energy payback and costly in financial terms. We can do this fairly easily if we invest in more innovative methods for making and installing the towers and foundations that support them".

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Renewable energy sparks new interest from investors

au.news.yahoo.com
20 Aug 2012

Australia is tipped to figure prominently in takeover activity across the power utility sector over the next couple of years as investors eye renewable energy assets and the NSW privatisation. PricewaterhouseCooper's half-yearly analysis of the Asia Pacific power sector out today says the new carbon tax and the plan to source 20% of Australia's electricity from renewable sources by 2020 is fuelling interest in renewable energy assets.

There is also a growing focus on the proposed privatisation of NSW's remaining power stations. PwC says interest is both from Australian energy retailers and "a number of Asian players looking at the opportunity to acquire substantial generation capacity".

Chinese companies could figure prominently as they are increasingly looking for growth offshore to make up for domestic tariff restrictions which limit their ability to pass on costs. Both Chinese and Japanese groups have been active in Australia over the past few years, including China Shenhua's purchase of windfarms in Tasmania last year.

The value of M&A deals in the Asia Pacific sector more than tripled in the June half to $US23.6 billion ($22.6 billion) from $US7.5 billion for the same time last year. But $US12.5 billion of the latest figure was attributable to the partial nationalisation of the scandal-plagued Tokyo Electrical Power Company in the wake of last year's earthquake and tsunami. Significantly, deal-making in renewable energy held firm during the June half at $US680 million, while the rest of the world more than halved.

As smart electric grid evolves, engineers show how to include solar technologies

phys.org
17 Aug 2012

Reza Arghandeh of Blacksburg, Va., a doctoral candidate in the Bradley Department of Electrical and Computer Engineering at Virginia Tech, won the best student paper award at the 20th International Conference on Nuclear Engineering, held in conjunction with the American Society of Mechanical Engineering Power 2012 Conference at Anaheim, Calif.. His advisor is Robert Broadwater, professor of electrical and computer engineering, who specializes in electric power system analysis and design.

In their paper, they acknowledge that solar power resources are "intermittent, seasonal, and non-dispatchable". However, the current national climate with its deregulation policies, electricity tariffs, control strategies and demand management are "significant tools for flexible and resilient operation of power systems with photovoltaic adoption levels", Arghandeh argued.

"Selling the household generated electricity into the electric energy market and the storage of electricity in storage systems and demand control systems provide a variety of economic opportunities for customers and utility companies to use more renewable resources", he added.

Some residential houses are already doing just this-selling power back to an electrical distribution industry. But Arghandeh and Broadwater's work provides an optimization algorithm for a Distributed Energy Storage (DES) system on a broad scale. The system they developed presents a fleet of batteries connected to distribution transformers. The storage system can then be used for withholding distributed photovoltaic power before it is bid to market, Arghandeh explained.

"Withholding distributed photovoltaic power, probably gained from rooftop panels, represents a gaming method to realize higher revenues due to the time varying cost of electricity", he said.

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Solar electricity generation makes a lot of cents

www.power-eng.com
12 Aug 2012

The outlook for makers of photovoltaic cells is much sunnier in Australia than New Zealand. feed-in tariffs in Australia, which see homeowners paid good prices for what energy their solar panels produce above what they use, has driven a 431% increase in the installations of solar panels there since 2010. In New Zealand, there are about 20,000 solar installations-just over 1% of the country's 1.6 million houses. Europe accounts for about 71% of the world's installed solar capacity.

Roy and Jenny Gardner installed 10 solar panels on their southern English home about a year ago and expect to see the scheme pay for itself in under a decade. "They make enough money to pay for our electricity annually", Mrs Gardner said. "We are paid 43 pence [86¢] for every unit generated and a further 3 pence [6¢] for half the units produced. The government has since been cutting down on the units paid and anyone now investing in this scheme will now only be paid 16 pence [32¢] a unit".

Despite the cut, Ivan Posa, who spent $25,000 on 20 solar panels at his Hamilton home three years ago, envies the British scheme. His family bulldozed an old home on their rural Tuhikaramea Rd section two years ago and began building a four-bedroom home which they crowned with 20 solar panels.

Solar power, installed by specialists What Power Crisis, were complemented by a $20,000 wind turbine which, together, should make the Posas self sufficient. Mr Posa, a retired farmer, cannot be certain how self sufficient he, wife Deb, and children Mili, 17, and Zach, 15, are but guesses it is about 80% at the moment. That is with an unfinished house and underfloor heating, an idea borrowed from ancient Rome, which Mr Posa jokes would cause the lights in Hamilton to go out if it was turned on full bore.

"When I started the house building I thought it was an opportunity to install solar panels from the start", he said. "It's hard to work out where power pricing is going to go and the price of panels is relatively competitive at the moment". In fact, the cost of photovoltaic cells has fallen by about 80% this year to about $1.25 a watt, causing the likes of WEL Networks to investigate the economic viability of building solar power stations in the region.

WEL Networks chief executive Dr Julian Elder said the British market had experienced unprecedented growth. "New Zealand is well behind Europe due to many factors, but mainly the lack of feed-in tariffs and subsidies". At the moment an abundance of renewable energy, such as hydroelectric and wind, meant it was more cost-effective for power generators to expand existing facilities such as the Te Uku wind farm. Mark Hanson, acting communications manager for retail at Mighty River Power, said the state-owned company was not involved in any form of solar power investigation. "The company's priority is with its geothermal programme and potential wind farm developments,' he said.

Energy Efficiency and Conservation Authority chief executive Mike Underhill said: "We have a high amount of untapped large-scale renewable energy. The other thing that we have got is a high number of renewable power stations. There's 3000 MWs of current available from consented sites and if they come off that's where the new generation is going to come from for the next 15 to 20 years".

But from a homeowner's perspective, hooking a home up to solar panels is a no-brainer. Just three weeks ago a similar sized photovoltaic project at the Forlong family home in Howden Rd, Frankton, where the same company installed 18 solar panels, cost $12,000. Dad Howard Forlong, a director at Forlongs department store in Frankton, got the idea from a stall at the National Agricultural Fieldays.

When he sat down with a chartered accountant he realised that installing the panels at the house he shares with his wife, Helen, and children Harrison, 17, Stephanie, 16, and Jonathan, 13, would pay for itself in about seven years. "It's got a 9.6% return on investment, compared to 4% if I put it in the bank". he said.

In the three weeks since he threw the switch he has saved $22 on his power bill. As well as generating their own electricity, both the Posa and Forlong families receive a one-for-one credit for energy they do not use that is fed into the national grid. That means their solar panels can earn them money on a sunny day when they are out or on holiday. "We are on an import and export tariff", Mr Posa said. "We tend to use a lot more [and export less] in the winter and use a lot less [and export more] in the summer. It's hard for us to put an exact figure on it at the moment".

Britton Broun, media adviser to the Economic Development Group for the Business, Innovation and Employment Ministry, said New Zealand differed from other countries as it had a national electricity system dominated by grid-scale renewable generation. "Last year, 77% of New Zealand's electricity came from renewable sources. This is one of the highest levels of renewable electricity generation in the OECD [Organisation for Economic Co-operation and Development].

"The government has a target of generating 90% of electricity from renewable sources by 2025, so more grid-scale renewable electricity generation is anticipated. Consequently, there is less drive for domestic-scale renewable electricity generation here than in many other countries. Instead, the government's push has tended to be for more energy-efficient homes through insulation standards, efficient household heating, and encouraging energy efficiency".