Why Having Solar Power In The Home Is Easier Than You Think

A million British homes now use solar energy. Whether it is solar power or thermal, the sun’s rays are powering energy production like never before.

According to Carbon Brief, from April to September last year more energy was produced by solar panels on fields and homes than fossil fuels in the UK.

It was an historic first, but it won’t be the last we hear of solar marking milestones. With experts predicting 10 million homes across the UK will have solar panels by 2020, now is a better time than any to make the switch.

Before installing solar panels in your home there are few questions to consider.

For starters, there are two types of panels: solar thermal or photovoltaic. The first use the sun’s energy to heat water and the latter are modules made up of photovoltaic cells that convert sunlight directly into electricity.

How many trees surround your property? And does your neighbour’s property shade parts of your own? This is a big consideration before placing that order and deciding where best to install panels.

You should also consider insolation – this is a measure of how much solar radiation reaches ground level under a specified time limit. This will be a good gauge of how many panels you actually need.

“There should be an initial comprehensive survey that should clearly establish the roof condition and structure. A mid-range large domestic PV 4kW system is around £6,000. It’s pretty quick to install solar these days – it can be done in as little as half a day (though scaffolding may be there for longer),” advises Leonie Greene, Head of External Affairs at Solar Trade Association UK (STA).

There is a common misconception that installing and maintaining solar panels will drain both your time and bank balance. But a report carried out by the Grantham Institute at Imperial College London and the Carbon Tracker Initiative found that the cost of solar has fallen by 85 percent in seven years.

With low cost an attractive feature, they predict solar panels could supply 23 percent of global power generation by 2040, and 29 percent by 2050.

Luckily, there is very little maintenance involved with solar panelling. According to CalFinder, dust build-up on your rooftop solar panels can reduce electricity production by seven percent.

But there’s no need to climb up to your roof, a hose down from the ground should suffice – or the rain will wash them for you. The life expectancy of panels is about 25 years so it’s a solid investment.

If you use electrical appliances in your home during the day, they will draw electricity straight from your panels. If you use electricity at night, then they take energy from the national grid and increases your energy bills. But this is set to change.

“There are currently around 4,000 domestic storage units in the UK. We are expecting these to become cost-competitive in the next couple of years and this market will take off. That means that householders will be able to use the solar power that they generate during the day in the evening,” confirms Greene.

If you are curious to know how much money you could save from home solar panels then the Energy Saving Trust solar energy calculator can help.

Perhaps the most important consideration is that solar power significantly reduces carbon emissions.

“[It’s about] the sheer necessity of doing your bit to replace polluting power with clean power – it can’t happen fast enough for the climate,” explains Greene.

“[It’s about] the satisfaction of independence; taking control of your own energy supply and being less at the mercy of energy utilities and volatile fossil prices. And increasingly the aesthetics of solar power are a big attraction – the newer in-roof products and solar tiles are extremely attractive.”

Electrify the World is a Nissan initiative. As a pioneer of electric vehicles, Nissan believes in acting now for a more sustainable future. Read more about electric living and sustainability.

single catalyst to produce both , hydrogen and oxygen gas 24 hours a day seven days a week

By Mark Shwartz 

Stanford scientists have developed a cheap and efficient way to extract clean-burning hydrogen fuel from water 24 hours a day, seven days a week. 

Stanford University scientists have invented a low-cost water splitter that uses a single catalyst to produce both , hydrogen and oxygen gas 24 hours a day seven days a week. 

The device, described in a study published June 23 in "Nature Communications", could provide a renewable source of clean-burning hydrogen fuel for transportation and industry. 

"We have developed a low-voltage, single-catalyst water splitter that continuously generates hydrogen and oxygen for more than 200 hours, an exciting world-record performance," said study co-author Yi Cui, an associate professor of materials science and engineering at Stanford and of photon science at the SLAC National Accelerator Laboratory. 

In an engineering first, Cui and his colleagues used lithium-ion battery technology to create one low-cost catalyst that is capable of driving the entire water-splitting reaction. (See video.) 

"Our group has pioneered the idea of using lithium-ion batteries to search for catalysts," Cui said. "Our hope is that this technique will lead to the discovery of new catalysts for other reactions beyond water splitting." 

Clean hydrogen

Hydrogen has long been promoted as an emissions-free alternative to gasoline. 

Despite its sustainable reputation, most commercial-grade hydrogen is made from natural gas, a fossil fuel that contributes to global warming. As an alternative, scientists have been trying to develop a cheap and efficient way to extract pure hydrogen from water. 

A conventional water-splitting device consists of two electrodes submerged in a water-based electrolyte. A low-voltage current applied to the electrodes drives a catalytic reaction that separates molecules of H2O, releasing bubbles of hydrogen on one electrode and oxygen on the other. 

Each electrode is embedded with a different catalyst, typically platinum and iridium, two rare and costly metals. But in 2014, Stanford chemist Hongjie Dai developed a water splitter made of inexpensive nickel and iron that runs on an ordinary 1.5-volt battery. 

Single catalyst

In the new study, Cui and his colleagues advanced that technology further. 

"Our water splitter is unique because we only use one catalyst, nickel-iron oxide, for both electrodes," said graduate student Haotian Wang, lead author of the study. "This bi-functional catalyst can split water continuously for more than a week with a steady input of just 1.5 volts of electricity. That's an unprecedented water-splitting efficiency of 82 percent at room temperature." 

In conventional water splitters, the hydrogen and oxygen catalysts often require different electrolytes with different pH - one acidic, one alkaline - to remain stable and active. "For practical water splitting, an expensive barrier is needed to separate the two electrolytes, adding to the cost of the device," Wang said. "But our single-catalyst water splitter operates efficiently in one electrolyte with a uniform pH." 

Wang and his colleagues discovered that nickel-iron oxide, which is cheap and easy to produce, is actually more stable than some commercial catalysts made of precious metals. 

"We built a conventional water splitter with two benchmark catalysts, one platinum and one iridium," Wang said. "At first the device only needed 1.56 volts of electricity to split water, but within 30 hours we had to increase the voltage nearly 40 percent. That's a significant loss of efficiency." 

Marriage of batteries, catalysis

To find catalytic material suitable for both electrodes, the Stanford team borrowed a technique used in battery research called lithium-induced electrochemical tuning. The idea is to use lithium ions to chemically break the metal oxide catalyst into smaller and smaller pieces. 

"Breaking down metal oxide into tiny particles increases its surface area and exposes lots of ultra-small, interconnected grain boundaries that become active sites for the water-splitting catalytic reaction," Cui said. "This process creates tiny particles that are strongly connected, so the catalyst has very good electrical conductivity and stability." 

Wang used electrochemical tuning - putting lithium in, taking lithium out - to test the catalytic potential of several metal oxides. 

"Haotian eventually discovered that nickel-iron oxide is a world-record performing material that can catalyze both the hydrogen and the oxygen reaction," Cui said. "No other catalyst can do this with such great performance." 

Using one catalyst made of nickel and iron has significant implications in terms of cost, he added. 

"Not only are the materials cheaper, but having a single catalyst also reduces two sets of capital investment to one," Cui said. "We believe that electrochemical tuning can be used to find new catalysts for other chemical fuels beyond hydrogen. The technique has been used in battery research for many years, but it's a new approach for catalysis. The marriage of these two fields is very powerful." 

Other Stanford co-authors of the study are postdoctoral scholar Hyun-Wook Lee, visiting student Zhiyi Lu and graduate students Yong Deng, Po-Chun Hsu, Yayuan Liu and Dingchang Lin. 

Support was provided by the Global Climate and Energy Project at Stanford and the Stanford Interdisciplinary Graduate Fellowship program. 

Source: Stanford