Kenya: Solar Power Provider Connects 250,000 Homes to Its Network

A local pay-as-you-go off grid energy provider has announced connecting 250,000 homes across Kenya, Uganda and Tanzania.

M-Kopa Solar, which provides a payment plan for supply of a solar lighting system, a radio and phone charging apparatus, said the achievement is in line with its target of connecting a million customers to its solar power systems by 2018.

The firm's managing director and co-founder, Mr Jesse Moore, said the growth in connected customers is satisfactory as the region shifts focus on renewable energy.

"Last September, we celebrated 100,000 customers, and a year later we are already at a quarter-million. With hundreds of great customers coming on board every day, we are helping East Africa leapfrog over the grid to enjoy cheaper, cleaner, and more reliable solar power," Mr Moore said.

FAST-GROWING PROVIDER

Kenya is emerging as a hot spot for off-grid solar power. A 2014 study by M-Kopa Solar and InterMedia showed that 14 per cent of the surveyed population use solar as their primary lighting and charging source.

M-Kopa is one of the fastest-growing power providers in the region, connecting power to over 500 new homes each day.

The battery-powered 8W home system has three lights, a phone-charging facility and a chargeable radio.

The savings generated by using off grid solar over kerosene are said to be substantial for individual households and the broader East African economy.

ESTIMATED SAVINGS

Each M-Kopa Solar home is calculated to save $750, compared to using kerosene over a four-year period.

This means that the combined projected savings by the 250,000 households using the system is $187 million.

Nairobi-headquartered, M-Kopa Solar now has a network of over 1,500 direct sales agents and 100 customer service centres across Kenya, Uganda and Tanzania.

Dailynation

How the local yeasts can affect the flavour and aroma of wine

Mmmm, I think I can detect a kiwi yeast in that Sauvignon Blanc. A winemaker’s practices and the climate tend to get much of the credit for the taste or aroma of a wine, but research is starting to show just how important microbes can be for creating a distinctive taste.

The characteristics of the environment where a crop grows and the methods of a winemaker are collectively known as the terroir. They are known to influence the taste of products such as wine, coffee and cocoa.

Even though we know microbes affect crops as they grow and different types of yeasts are used to create different tastes during the fermentation process, studies into the contribution of local microbes are only just starting to kick off, says Matthew Goddard from the University of Lincoln.

Previous research by Goddard and Sarah Knight at the University of Auckland in New Zealand has shown that there are different varieties of the yeast Saccharomyces cerevisiae in vineyards in different regions in New Zealand. But it was unclear whether and how they affected the wine produced from grapes grown in those areas.
That special 10 per cent

Now they have isolated yeast from six regions and used them to ferment the same batch of grape juice from Sauvignon Blanc fruit, which has been sterilised to kill off any existing microbes.

Then they analysed the concentrations of 39 flavour-imparting chemicals in wines produced from the different yeasts. They found that 29 of the compounds varied depending on where the yeast had come from, suggesting that the local varieties of yeast affect the taste of wine, and play a part in determining its terroir. This explained around 10 per cent of variation in chemical profiles of wines.

Many winemakers already buy commercial wine yeast from other regions, but their impact is probably small compared with geography, Goddard says. “The microbial component is only one of many influences, so by itself wouldn’t weigh in massively. But we’re suggesting here that even though it’s a small component it’s still a significant component.”

Hervé Alexandre from the University of Burgundy in Dijon, France, agrees that soil and climate play a bigger role inthe terroir.
Bubbling away

Fermentation is often done using the strains of yeast present on the grapes when they are harvested, and their numbers may vary from year to year, he says, but we still get the same wine signature. “This tends to support the idea that the terroir effect is mainly driven by more important factors than yeast,” he says.

Other big taste influences will come from human-influenced factors, such as when the grapes are picked, the blend of grapes or wines, whether and for how long the wine is matured in barrels and how long it is in the bottle.

S. cerevisiae, which turns sugar from the grapes into alcohol, and affects the breakdown of many flavour-related chemical compounds, isn’t the only microbe that has a role in determining the wine’s flavour. Many other soil microbes are associated with vines as they grow, and their effects on grapes has been poorly studied.

“It seems conceivable, if not probable to me, that many of these microbes will be affecting the way the crop develops,” says Goddard. And the way that crop develops will affect things such as its taste and flavour.

He says the findings highlight an economic argument for preserving biodiversity within areas that produce agricultural products. “Here we show that the unique collection of microbes in an area contributes to the value of that product. So if you erode the uniqueness of biodiversity in an area you might erode the uniqueness of your product and thus the value.”


Journal reference: Scientific Reports, DOI: 10.1038/srep14233

Newscientist.com

Deepest earthquakes seem to be seasonal but we don’t know why

Some earthquakes seem to hit in a seasonal pattern – and no one knows why.

Zhongwen Zhan of the California Institute of Technology and Peter Shearer of the Scripps Institution of Oceanography examined a global catalogue of earthquakes that have occurred since 1900. Out of 60 large, deep earthquakes in the catalogue, 42 occurred between the months of April and October.

The seasonal trend doesn’t appear in shallower earthquakes or in smaller tremors, but stands out clearly for earthquakes above magnitude 7.0 and at a depth greater than 500 kilometres. An explanation remains elusive. “Physically, it doesn’t make any sense,” Zhan says.


It could be related to the tidal forces felt by Earth due to the sun’s gravity, Zhan says, or possibly due to a wobble in Earth’s rotational axis due to seasonal sloshing of water and air around the planet.

Stresses generated by either force are small compared with the daily and monthly forces exerted by the moon, Zhan says. But if it is down to solar tides then this may explain how earthquakes happen in a part of Earth where they aren’t expected.

That’s because at depths between 500 and 700 kilometres, the rocks are under high temperatures and pressures that should render them soft and pliable &ndash and unlikely to suddenly rupture and cause a quake. “The high pressure makes people think there shouldn’t be any earthquakes,” Zhan says.

Tidal nudge

Solar tidal forces may provide the nudge needed to trigger a deep earthquake. “That means that [the earthquake] nucleation process is very sensitive to small stress perturbations,” Zhan says.

As early as the 1930s, geologists claimed to have found a seasonal trend in earthquake activity. Often, as decades pass and new data comes to light, the correlations weaken, says Cliff Frohlich of the University of Texas at Austin.

Although Zhan’s methods are sound the result may only be a statistical aberration, and lacks a physical mechanism, Frohlich says. “If you’re searching for some possible explanation, the solar tide would be your candidate,” he says. “But it’s not a very strong candidate because it’s not a very strong tide.”

Zhan found that the seasonal trend is stronger in some regions than others. Almost all of the large, deep earthquakes near Japan fell between April and October, for example, while earthquakes near Tonga were spread more evenly through the year.

He says that it will only take a few more decades of earthquake data to see whether the seasonal trend is an actual phenomenon or just random chance. A 30 May earthquake, centred in the Bonin Islands 1000 kilometres south of Tokyo, is already a candidate for inclusion in the data set.

A confirmed trend may lead to earthquake prediction tools, Zhan says. “Studying these deep earthquakes may help us understand the earthquake nucleation process in general, therefore helping understanding large shallow earthquakes too, which are much more damaging.”

Journal reference: Geophysical Research Letters, DOI: 10.1002/2015GL065088

Newscientist.com

Oilsands may face severe water shortages, Athabasca River study suggests

'The river is much more variable than you would think based on measurements since 1950s'

The Athabasca River, highway construction and suburbs seen from a helicopter in Fort McMurray, Alta., on July 10, 2012. Water for the oilsands industry comes mainly from northern Alberta's Athabasca River, and oilsands account for 72 per cent of estimated water use from the river. (Jeff McIntosh/Canadian Press)

The river that provides water to the oilsands industry is much more prone to multi-year droughts than modern records show, suggesting that the industry's current level of water use may not be sustainable, a new study suggests.

The oilsands industry needs 3.1 barrels of fresh water to produce a barrel of crude oil from oilsands mining and 0.4 barrels of fresh water to produce a barrel of crude oil from oilsands drilling, according to the Canadian Association of Petroleum Producers.

That water comes mainly from northern Alberta's Athabasca River, and oilsands account for 72 per cent of estimated water use from the river.

University of Regina researcher David Sauchyn holds a cross-section of a tree, showing its growth rings, which provide a record of available water in the Athabasca Basin over the years. (Courtesy David Sauchyn)

The government regulates the amount of water the oilsands industry is allowed to use based on measurements of water flow taken by dozens of monitoring stations along the river since 1957.

But a study led by University of Regina researcher David Sauchyn has found that those water flow measurements aren't that representative of the river's long-term behaviour.

"What we show is if you go back 900 years, the river is much more variable than you would think based on measurements since 1950s," Sauchyn said.

The oilsands industry needs 3.1 barrels of fresh water to produce a barrel of crude oil from oilsands mining. (Jeff McIntosh/Canadian Press)

In order to get centuries' worth of data, Sauchyn and his colleagues drilled pencil-sized cores from live trees and cut cross sections of dead trees to measure their rings. They sampled hundreds of very old Douglas firs and limber pine trees growing on the dry slopes in the upper part of the Athabasca basin. Some of them had started growing as long ago as the year 1111.

The trees put on one growth ring every year. The ring is thicker if the growing conditions are better and thinner if the tree grows less due to a shortage of sunlight, nutrients, heat or water.

"On the prairies in summer, there's plenty of everything except water," Sauchyn said, "so really what the growth of the trees tell us is how much water was available to the tree every year over its lifespan. It's the same water that's available to the river as well."

The researchers compared the "climate record" found in the tree rings to measured water flows in the Athabasca River since 1952 and found a very close correlation. They then used that to estimate water flows going back 900 years.

Decades-long droughts

The study also confirmed that overall flows in the Athabasca River are declining. That's something that was already known and thought to be mainly because of the melting and shrinking of glaciers, seen in this photo of the river's headwaters. (David Sauchyn)

What they found were records of droughts that lasted years to decades, including relatively recent severe droughts from 1888-96 and another one from 1790 to 1806, when river flows were lower than the minimum ever recorded by modern instruments.

Some droughts in previous centuries were even worse, lasting up to half a century.

"That is something we just haven't experienced, when we do it's going to be difficult because we're not used to it," Stauchyn said, "but also because it will reoccur in a much warmer climate than in the past — a double whammy."

The results were published in the journal Proceedings of the National Academy of Sciences.

• Summary of the paper in PNAS

At the moment, the oilsands industry is allowed to take 4.4 per cent of the mean annual flow of the Athabasca River. According to Lisa Glover, a spokeswoman for Alberta Environment and Parks, that's based on the maximum amount of water a mine project could expect to need at any stage of its development rather than its typical use. Because of that, the industry typically uses far less. In 2011, it used 143 million cubic metres, or 17 per cent of its allowance, the government says.

Still, that could represent a significant proportion of the water in the river in case of a severe drought, Sauchyn says.

He and his colleagues recommend that the government and oilsands industry consider what they would do in case of a long drought in a warmer climate.

Glover said that water licences issued to oilsands companies are already reviewed under certain conditions, but the allocations aren't adjusted on a regular basis. "This approach better reflects the long-term nature of oil sands projects," Glover wrote.

Sauchyn and his colleagues looked at the tree rings of hundreds of very old Douglas firs and limber pine trees growing on the dry slopes in the upper part of the Athabasca basin. Some of them had started growing as far back as 1111. (Courtesy David Sauchyn)

The study also confirmed that overall flows in the Athabasca River are declining. That's something that was already known and thought to be mainly because of the melting and shrinking of glaciers.

The Alberta Energy Regulator already has regulations in place torestrict water use by the oilsands industry in the short term when there are low water levels. That happened this summer in the North Athabasca basin. Companies in the lower Athabasca region were not affected.

According to the Alberta Energy Regulator, oilsands companies already recycle 80 to 95 per cent of the water they use.

Sauchyn acknowledged that the industry is working to reduce its water consumption.

"Which is a good idea," he added, "and we're giving them more reason to use less water."

The study was funded in part by the oilsands industry via the Canadian Oil Sands Innovation Alliance, along with the Natural Sciences and Engineering Research Council of Canada and the Meteorological Survey of Canada.

Sauchyn and his colleagues looked at the tree rings of hundreds of very old Douglas firs and limber pine trees growing on the dry slopes in the upper part of the Athabasca basin. Some of them had started growing as far back as 1111. (Courtesy David Sauchyn)

Credit: cbc.ca/news/technology