Tag: investors

4 of the most exciting emerging technologies in electricity generation

6 July 2017

Power generation

Since the dawn of the industrial age, the world has been powered by a relatively small set of technologies. The 20^th century was the age of coal, but this side of 2000, that’s changed.

The need to curb emissions and the rise of renewables, from wind to solar to biomass, has significantly changed how we fuel our power generation.

Today, some of the world’s most interesting and exciting emerging technologies are those designed to generate electricity.

Microbial fuel cells – harnessing the power of bacteria

Bacteria are all around us. Some are harmful, some are beneficial, but all of them ‘breathe’. When they breathe oxidation occurs, which is when something combines with oxygen at a chemical level, and when bacteria do this, electrons are released.

By connecting breathing microbes to a cathode and an anode (the positive and negative rods of a battery), the flow of these released electrons can be harnessed to generate power. This is what’s known as a microbial fuel cell (MFC). MFCs are used largely to generate electricity from waste water, but are expanding into more exotic uses, like powering miniature aquatic robots.

New developments are constantly expanding the power and applications of MFCs. Researchers at Binghamton University, New York found that combining phototropic (light-consuming) and heterotrophic (matter-consuming) bacteria in microbial fuel reactions generates currents 70 times more powerful than in conventional setups.

Solar – a new dawn

Solar power may not be a new technology, but where it’s going is.

One of the most promising developments in the space is solar voltaic glass, which has the properties of a sheet of window glass but can also generate solar power.

Rather than collecting photons like normal solar does (and which transparent materials by definition can’t do) photovoltaic glass uses salts to absorb energy from non-visible wavelengths and deflects these to conventional solar cells embedded at the edge of each panel.

Or there’s solar PV paint, which contains tiny light sensitive particles coated with conductive materials. When layered over electrodes you’ve got a spray-on power generator.

Betavoltaics – nothing wasted from nuclear waste

Nuclear material is constantly decaying and in the process emits radioactive particles. This is why extremely radioactive material is so dangerous and why properly storing nuclear waste is so important and so expensive. But this waste can actually be put to good use. Betavoltaic devices use the waste particles produced by low-level radioactive materials to capture electrons and generate electricity.

The output from these devices can be fairly low and decreases over long periods of time, but because of the consistent output of nuclear decay they can be extremely long-lasting. For example, one betavoltaic battery could provide one watt of power continuously for 30 years.

And while they aren’t currently fit to work on a large scale, their longevity (and very compact size) make them ideal power sources for devices such as sensors installed on equipment that needs to be operational for long periods.

Tidal power – changing tides

A more predictable power source than intermittent renewables like wind and solar, tidal power isn’t new, however its growth and development has typically been restrained by high costs and limited availability. That’s changing. Last year saw the launch of the first of 269 1.5 MW (megawatt) underwater turbines, part of world’s first large scale tidal energy farm in Scotland.

Around the world there are existing tidal power stations – such as the Sihwa Lake Tidal Power Station in South Korea, which has a capacity of 254MW – but the MeyGen array in Scotland will be able to take the potential of the technology further. It’s hoped that when fully operational it will generate 398MW, or enough to power 175,000 homes.

We might not know exactly how the electricity of tomorrow will be generated, but it’s likely some or all of these technologies will play a part. What is clear is that our energy is changing.

This is how you unload a wood chip truck

30 June 2017

Sustainable bioenergy

A truck arrives at an industrial facility deep in the expanding forestland of the south-eastern USA. It passes through a set of gates, over a massive scale, then onto a metal platform.

The driver steps out and pushes a button on a nearby console. Slowly, the platform beneath the truck tilts and rises. As it does, the truck’s cargo empties into a large container behind it. Two minutes later it’s empty.

This is how you unload a wood fuel truck at Drax Biomass’ compressed wood pellet plants in Louisiana and Mississippi.

What is a tipper?

“Some people call them truck dumpers, but it depends on who you talk to,” says Jim Stemple, Senior Director of Procurement at Drax Biomass. “We just call it the tipper.” Regardless of what it’s called, what the tipper does is easy to explain: it lifts trucks and uses the power of gravity to empty them quickly and efficiently.

The sight of a truck being lifted into the air might be a rare one across the Atlantic, however at industrial facilities in the United States it’s more common. “Tippers are used to unload trucks carrying cargo such as corn, grain, and gravel,” Stemple explains. “Basically anything that can be unloaded just by tipping.”

Both of Drax Biomass’ two operational pellet facilities (a third is currently idle while being upgraded) use tippers to unload the daily deliveries of bark – known in the forestry industry as hog fuel, which is used to heat the plants’ wood chip dryers – sawdust and raw wood chips, which are used to make the compressed wood pellets.

How does it work?

The tipper uses hydraulic pistons to lift the truck platform at one end while the truck itself rests against a reinforced barrier at the other. To ensure safety, each vehicle must be reinforced at the very end (where the load is emptying from) so they can hold the weight of the truck above it as it tips.

Each tipper can lift up to 60 tonnes and can accommodate vehicles over 50 feet long. Once tipped far enough (each platform tips to a roughly 60-degree angle), the renewable fuel begins to unload and a diverter guides it to one of two places depending on what it will be used for.

“One way takes it to the chip and sawdust piles – which then goes through the pelleting process of the hammer mills, the dryer and the pellet mill,” says Stemple. “The other way takes it to the fuel pile, which goes to the furnace.”

The furnace heats the dryer which ensures wood chips have a moisture level between 11.5% and 12% before they go through the pelleting process.

“If everything goes right you can tip four to five trucks an hour,” says Stemple. From full and tipping to empty and exiting takes only a few minutes before the trucks are on the road to pick up another load.

Efficiency benefits

Using the power of gravity to unload a truck might seem a rudimentary approach, but it’s also an efficient one. Firstly, there’s the speed it allows. Multiple trucks can arrive and unload every hour. And because cargo is delivered straight into the system, there’s no time lost between unloading the wood from truck to container to system.

Secondly, for the truck owners, the benefits are they don’t need to carry out costly hydraulic maintenance on their trucks. Instead, it’s just the tipper – one piece of equipment – which is maintained to keep operations on track.

However, there is one thing drivers need to be wary of: what they leave in their driver cabins. Open coffee cups, food containers – anything not firmly secured – all quickly become potential hazards once the tipper comes into play.

“I guess leaving something like that in the cab only happens once,” Stemple says. “The first time a trucker has to clean out a mess from his cab is probably the last time.”

3 ways decarbonisation could change the world

27 June 2017

Sustainable business

Mitigating climate change is a difficult challenge. But it’s one well within the grasp of governments, companies and individuals around the world if we can start thinking strategically.

On the behalf of the German government, The Internal Energy Agency (IEA) and the International Renewable Energy Agency (IRENA) have jointly published a report outlining the long-term targets of a worldwide decarbonisation process, and how those targets can be achieved through long-term investment and policy strategies.

At the heart of the report is a commitment to the ‘66% two degrees Celsius scenario’, which the report defines as, ‘limiting the rise in global mean temperature to two degrees Celsius by 2100 with a probability of 66%’. This is in line with the Paris Agreement, which agreed on limiting global average temperature increase to below two degrees Celsius.

Here are three of the findings from the report that highlight how decarbonisation could change the world.

The energy landscape will change – and that’s a good thing

Decarbonisation will by definition mean reducing the use of carbon-intensive fossil fuels. Today, 81% of the world’s power is generated by fossil fuels. But by 2050, that will need to come down to 39% to meet the 66% two degrees Celsius scenario, according to the report. But, this doesn’t mean all fossil fuels will be treated equally.

Coal will be the most extensively reduced, while other fossil fuels will be less affected. Oil use in 2050 is expected to stand at 45% of today’s levels, but will likely still feature in the energy landscape due its use in industries like petrochemicals.

Gas will likely also remain a key part of the energy makeup, thanks to its ability to provide auxiliary grid functions like frequency response and black-starting in the event of grid failure.

Renewables like biomass will likely play an increasing role here as well, particularly when combined with carbon capture and storage (CCS) technology.

Overall, renewable energy sources will need to increase substantially. In the report’s global roadmap for the future, renewables make up two thirds of the primary energy supply. Reaching this figure will be no mean feat – it will mean renewable growth rates doubling compared with today.

Everyday electricity use will become more efficient

The report highlights the need for ‘end-use’ behaviour to change. This can mean everyday energy users choosing to use a bit less heat, power and fuel for transport in our day-to-day activities, but a bigger driver of change will be by investment in better, more efficient end-use technology – the technology, devices and household appliances we use every day.

In fact, the study argues that net investment in energy supply doesn’t need to increase beyond today’s level – what needs to increase is investment in these technologies. For instance, by 2050, 70% of new cars must be electric cars to meet decarbonisation targets.

Infrastructure design could also be improved for energy efficiency – smart grids, battery storage and buildings retrofitted with energy efficient features such as LED lighting will be essential. There’s also the possibility of increased use of cleaner building materials and processes – for example, constructing large scale buildings out of wood rather than carbon-intensive materials such as concrete and steel.

Decarbonisation will cost, but not decarbonising will cost more

The upfront costs of meeting temperature targets will be substantial. A case study used in the report estimates that $119 trillion would need to be spent on low-carbon technologies between 2015 and 2050. But it also suggests another $29 trillion may be needed to meet targets.

However, failure to act could mean the world will pay out an even higher figure in healthcare costs, or in other economic costs associated with climate change, such as flood damage or drought. Therefore, the sum for decarbonisation could end up costing between two and six times less than what failing to decarbonise could cost.

On top of this, the new jobs (including those in renewable fuel industries that will replace those lost in fossil fuels) and opportunities that will be created between 2015 and 2050 could add $19 trillion to the global economy. More than that, global GDP could be increased by 0.8% in 2050, thanks to added stimulus from the low carbon economy.

Achieving a cleaner future won’t be easy – it requires planning, effort, and the will to see beyond short-term goals and think about the long-term benefits. But as the report demonstrates, get it right and the results could be considerable.

The biomass carbon story

Matthew Rivers, Director of Corporate Affairs, Drax, Group Special Advisor

23 February 2017

Sustainable bioenergy

There is an important difference between carbon dioxide (CO₂) emitted from coal (and other fossil fuels) and CO₂emitted from renewable sources. Both do emit CO₂ when burnt, but in climate change terms the impact of that CO₂is very different.

To understand this difference, it helps to think small and scale up. It helps to think of your own back garden.

One tree, every year for 30 years

Imagine you are lucky enough to have a garden with space for 30 trees. Three decades ago you decided to plant one tree per year, every year. In this example, each tree grows to maturity over thirty years so today you find yourself with a thriving copse with 30 trees at different stages of growth, ranging from one year to 30 years old.

At 30 years of age, the oldest has now reached maturity and you cut it down – in the spring, of course, before the sap rises – and leave the logs to dry over the summer. You plant a new seedling in its place. Through the summer and autumn the 29 established trees and the new seedling you planted continue to grow, absorbing carbon from the atmosphere to do so.

Winter comes and when it turns cold and dark you burn the seasoned wood to keep warm. Burning it will indeed emit carbon to the atmosphere. However, by end of the winter, the other 29 trees, plus the sapling you planted, will be at exactly the same stage of growth as the previous spring; contain the same amount of wood and hence the same amount of carbon.

As long as you fell and replant one tree every year on a 30-year cycle the atmosphere will see no extra CO₂and you’ll have used the energy captured by their growth to warm your home. Harvesting only what is grown is the essence of sustainable forest management.

If you didn’t have your seasoned, self-supplied wood to burn you might have been forced to burn coal or use more gas to heat your home. Over the course of the same winter these fuels would have emitted carbon to the atmosphere which endlessly accumulates – causing climate change.

Not only does your tree husbandry provide you with an endlessly renewable supply of fuel but you also might enjoy other benefits such as the shelter your trees provide and the diversity of wildlife they attract.

No added carbon

This is a simplified example, but the principles hold true whether your forest contains 30 trees or 300 million – the important point is that with these renewable carbon emissions, provided you take out less wood than is growing and you at least replace the trees you take out, you do not add new carbon to the atmosphere. That is not true with fossil fuels.

It is true that you could have chosen not to have trees. You could instead build a wind turbine or install solar panels on your land. That would be a perfectly reasonable choice but you’ll still need to use the coal at night when the sun doesn’t shine or when the wind isn’t blowing. Worst of all you don’t get all the other benefits of a thriving forest – its seasonal beauty and the habitat that’s maintained for wildlife.

Of course, the wood Drax needs doesn’t grow in our ‘garden’. We bring it many miles from areas where there are large sustainably managed forests and we carefully account for the carbon emissions in the harvesting, processing and transporting the fuel to Drax. That’s why we ‘only’ achieve more than 80% carbon savings compared to coal.

Tag: investors

4 of the most exciting emerging technologies in electricity generation