Keep the lights on with solar batteries
2013-03-08 18:51
Frankfurt - Renewable energy is constantly evolving and
challenging traditional utilities but one growing sector could make
home-generated power much easier to use and cut customers' dependence on energy
companies dramatically - solar batteries.
A major conundrum with solar panels has always been how
to keep the lights on when the sun isn't shining.
Solar batteries allow homes and businesses to store solar
power to use in the hours of darkness and can also help to create "smart
grids" that react to sudden power swings and free stored energy when
needed.
The technology is still expensive and not widely used but
with energy bills soaring for consumers, it could quickly gain market share and
reduce dependence on utilities, which are already struggling with overcapacity
and weak demand.
Italy has some of the highest power prices in Europe and
is looking at how to cut costs to allow its businesses to compete.
Nicola Cosciani, head of energy storage at Italy's top
industrial battery maker Fiamm, says heavy power users like cement and steel-makers
are looking at generating and storing their own solar power - and even selling
excess power from their batteries on to the grid.
"Germany and Italy will be explosive markets for
residential storage and big energy users are also starting to show an interest.
This is a game changer," he told Reuters.
By 2020, the EU aims to get 20% of its energy from
renewables.
That compares to 12.5% of the EU energy mix in 2010 and
8.1% in 2004, according to most recent EU statistics. Batteries will be crucial
in reaching this target.
In Germany, the world's largest solar market and Europe's
largest energy consumer, about 40% of all modules sold have been installed in
homes, directly hitting demand for power from E ON and RWE.
A four-person household can cut the amount of power it
uses from the grid by 30% per year if it uses solar panels and another 30% if
it uses a solar battery, leaving it to buy only 40% of supplies from utilities.
With power bills rising and solar subsidies and battery
prices falling, power storage is expected to expand dramatically within the
next two to four years.
Price falls
Solar batteries look like a large car battery and are
usually installed in the basement of a house, hooked up to a solar panel
outside and on to the grid with an inverter.
That allows the batteries to charge up and store excess
energy during the day and releases it in the evening. They can also release
surplus energy on to the grid.
The kit is still expensive but the price of solar panels
has already dropped two thirds in the last two years and the price of batteries
is expected to halve in the next few years.
A single solar battery costs about €800
per kilowatt hour, so an average 6kWh battery costs about €5 000.
Including installation, tax and components to connect it
to the grid, an average household - which consumes 3 500kWh per year - would
pay about €10 000
to €20 000
per storage system.
"We believe that lithium batteries will be available
for €400
to €500
per kilowatt hour in a few years, featuring a lifespan of 20 years," said
Martin Rothert, product manager at SMA Solar, Germany's largest solar company.
Solar batteries use either lead-acid or lithium-ion.
Germany plans to support the installation of solar
batteries with at least €50m in credit lines which will also support a greater
roll-out.
Italian energy consultant BIP said the battery market
will reach at least 9 000MW of capacity by 2020 from today's 270MW.
"Due to rising supply and awareness, we expect
several tens of thousands of these systems to be sold in Germany this
year," said Norbert Hahn, board member at IBC Solar.
Batteries are also needed to develop smart grids, which
adjust power supply to satisfy demand across the network.
Seeing the writing on the wall for traditional generation
and distribution, Italian utility Enel has done a deal with Japan's NEC - one
of the world's leading energy storage system makers - to roll out new
generation smart grids.
Developing smart grids can help cut costs and allow independent
renewable energy providers to sell their power into the grid. Renewable energy,
once capital costs are amortised, is cheaper and more secure.
"The idea is to apply the same principles of the
Internet to electricity networks - any device hooked up can send and receive
content," said Ugo Govigli, vice president for European smart grid
solutions for NEC Italia.
