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High-efficiency distribution transformers with on-load tap changers can help distribution network operators and owners of commercial distribution rings to secure supply in light of increasing voltage fluctuations from renewable energy generation.The growing popularity of wind and solar power is fundamentally changing the way distribution networks operate. Many traditional energy consumers – from businesses to homeowners – have now also become generators, feeding various amounts of energy into the grid, depending on the weather and their own consumption. This two-way flow of electricity is making it increasingly challenging for distribution network operators (DNOs) to maintain the optimal bandwidth. If the voltage drops too low, supply is effectively cut off. Overvoltage, however, could potentially damage vital electrical equipment.“Traditionally, energy generation would be stepped up by designated power plants according to predictable peaks in consumption, such as during the ad break of a popular television programme. However, the way that renewable energy is generated by many different parties today means that it can be difficult for DNOs to control when and how much energy is fed into the grid. Energy might be contributed at a time when grid voltage is already high, for example, or sometimes not at all. There have always been peaks and troughs in grid voltage but the difference between them is coming greater and more unpredictable,” says Erika Wilson, joint managing director of Wilson Power Solutions. “And so far we have only scratched the surface with renewable energy,” she adds. “The UK Conservative government has committed to switching off all coal fire electricity generation capacity by 2020 but we haven’t got the required renewable energy generation capacity already in the pipeline. Supply is going to become more and more insecure unless DNOs and private industrial or commercial owners of small distribution rings take steps to upgrade their infrastructure.”
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The 2385km Madeira HDVC link in Brazil is currently the longest power transmission line in the world. Image courtesy of ABB.

 Solar Power:

Solar costing Kiwis more

New Zealanders are increasingly turning to solar power ~ although experts warn the advantages of the systems come with costs and their popularity may be doing more harm than good for the environment.

There were 9533 solar connections in New Zealand at the end of March, up on 5760 at the same time last year and 2712 the previous year, according to the Electricity Authority.

Environment Centre Hawke’s Bay manager Sarah Grant said solar systems had several advantages. Their fuel source was free and would always be there, they required little maintenance and they were becoming more efficient.

The up-front capital cost of a solar system was high, but conventional power prices were increasing every year, so each year solar became a bit more realistic and worth the investment, she said.

Palmerston North City Council eco design advisor Nelson Lebo said a new home in an area away from powerlines could be a good candidate for solar power.

However, there were better ways for others to be sustainable.

Mr Lebo said research showed the carbon footprint of solar was around 10 times greater than geothermal or wind power. The manufacture of panels and frames in China used coal, he said.

“The bottom line is there’s heaps of better things people can invest in to save money and that are better for the environment.“

They could superinsulate ceilings, properly install curtains, use LED light bulbs and insulate hot water pipes, said Mr Lebo.

According to the Energy Efficiency and Conservation Authority, the main barrier to the uptake of solar energy was the cost.

Solar generation made up only 0.1 per cent of New Zealand’s total renewable energy.

Price reductions in solar equipment had made it more popular with homeowners.

A recent report by the Concept Consulting Group Ltd on the effect of solar panels on greenhouse gas emissions said solar photovoltaic (PV) uptake was expected to displace generation from existing fossil-fuelled stations and therefore reduce emissions, in the short-term.

However, it would have a limited effect in the medium term as uptake would substitute for new low emission power stations such as wind and geothermal.

This differed with most other countries because most of New Zealand’s electricity was generated from renewable sources and large-scale renewables represented the cheapest option for future electricity supply in New Zealand.

In the long term, PV was expected to modestly increase the need for fossil-fuelled generation because solar generated more power in summer than winter, the opposite of New Zealand’s power demand needs.

Of this year’s solar connections, 9022 were residential, 262 commercial and 249 industrial, according to the Electricity Authority.

Regardless of the cons, there would always be cases where the panels were seen as a win-win.

Thomas Hoskins of Hoskins Energy Systems in Wairarapa said the company had experienced a rise in solar installations over the past 10 years.

Customers Rose Hughes and husband Al built on a rural Greytown block five years ago. Mrs Hughes said the cost to add a transformer to the network as well a cable to the house would have been high. There was also a risk of maintenance costs given the rural nature of the site.

“We live within our power generating means and we have a greater understanding of the relationship between power generation and what we use.“ — By Kim Fulton

Northern Advocate May 21, 2016.

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AUSTRALIA: New closures bring coal figures down ► EUROPE: Common day-ahead for merged regions. ► AUSTRALIA: Green grass turns brown and the dams dry up .US: Make sure it has a local application ► INDIA: Punjab moves the solar goalposts. ► US: Casino lights glitter — dim everywhere else? ► CHINA: China’s solar power station in space. ► ENGLAND: Storms help power UK.JAPAN: Don't confuse Fukushima with a bomb! ► US: Coal gone in Oregan by 2040. ► AUSTRALIA: Hazelwood charged for smoke haze. ► AUSTRALIA: Solar plants to replace costly maintenace. ► SOUTH AFRICA: CSP project turn on in SA. ► JAPAN: Logitec breaks down before the starting blocks. ► US: Usage drops for 7th year in a row. ► US: High power. ► EUROPE: Where to from $5? Carbon betting ring thrashes around looking for an answer. ► CHINA: wind power going nowhere. ► US: Underpinning clean energy! .SCOTLAND: The last coal plant switches off its lights. ► JAPAN: Retail storm unleashed in Japan. ►
overseas stories

Despite the huff, bluster and headlines, wind generated power still only commanded 4.7% of net U.S. electric power generation last year. The headlines sprout it's growth (5.1% and albeit the smallest growth since 1999) — the reason being the weather patterns. According to the Energy Information Administration, the West had lowered wind speeds than in previous years, the opposite occurred in central parts of the US but the gains were not enough to offset the losses. However the spin was all positive countering it's important to note that wind power generation did rise overall in 2015. Last year, wind energy produced 191 terawatt hours, which represents about 4.7% of net US electric power generation. This is a 7% increase from 4.4% in 2014. In the renewable sources sector, wind trailed only hydropower as a source of electricity in the US last year. Additionally, 11 US states generated more than 10% of their overall electricity from wind last year. US electricity sourced by wind has increased each year since 1999. About 12.9% more wind capacity was added in the US in 2015.

Sweden’s Vattenfall has reported a 7% year-on-year increase in pre-tax earnings in its first quarter of 2016. The company said earnings before depreciation, amortisation and impairment losses (ebitda) of sek14.5bln ($1.8bln) - up from sek13.5bln in the same quarter of 2015. For its wind business, increased from sek1.3bln ($0.16bln) to sek1.5bln ($0.19) thanks to higher revenue and electricity generation after the completion of the DanTysk and Kentish Flats Extension offshore site and the Clashindarroch and Klim onshore projects. Generation increased year-on-year from 1.4TWh to 1.5TWh. The group is shifting towards a renewables and clean energy focused business, signified by the sale of its German lignite business earlier this month to Czech energy company EPH. “It is a year in which the transformation of Vattenfall will start in earnest, where the core is a climate-neutral generation portfolio, combined with customer-centred energy solutions. We are also planning bids for a number of substantial wind power projects. When this year is over it will be very interesting to see where we are,” Vattenfall CEO Magnus Hall said. For the 2015 financial year, the utility's wind division ebitda increased 22.5% in 2015, while the group recorded a sek23bln ($2.86bln) operating loss in its financial year due to impairment losses in its lignite, nuclear and coal businesses. — press release (30/4/2016)

PPL Electric Utilities on Wednesday (20/4/2016) completed the Northeast-Pocono Reliability Project, a $350m investment in new substations and power lines. Originally projected for completion in late 2017, the work was done more than a year early, however, while construction is complete, land restoration is expected to continue to the end of this year. The work included three new substations, nearly 60 miles of new 230-kilovolt power lines, and other improvements. Northeast-Pocono is the second major transmission project to be completed by PPL in the past year. The $648m Susquehanna-Roseland transmission line was completed in early May 2015. PPL Electric Utilities provides electric delivery service to more than 1.4m homes and businesses in Pennsylvania. With 2300 employees, PPL Electric Utilities is a subsidiary of PPL Corporation. PPL Electric.