The Future Of Energy Part 5: Alternative Sources

In part 1 of this series, I made a case for reducing our dependance on fossil fuels as much, and as soon, as possible. Since then I've been looking at ways this might be done.

So far I've looked at wind (part 2), and solar (part 3), but pointed out that these can only ever make up 20% of our total electric supply. This is because they are intermittent sources (i.e. not round the clock) and you can't run a modern society on an electric supply that shuts down over-night!

However, in part 4, I looked at energy storage, which could allow wind and solar to provide up to 100% of a country's electric. The trouble is, it may be a decade or more before energy storage has matured enough to allow this.

So what do we do until then? Well, for starters, keep adding to the wind turbines and solar power stations as fast as possible. It will take a while for most countries to reach their 20% thresholds anyway. By then, energy storage may be ready to go.

My concern is what happens if, for some reason, energy storage doesn't take off?


What we need is some form of energy that will allow us to quickly and easily replace existing coal fired power stations (which are the main problem). One that provides a constant rather than intermittent supply.

So let's have look at the options:

1) Hydroelectric: Dams have been generating electric since the early 1880s. In 2006, they produced around 20% of the world's electric and 88% of all renewable electric. They have a very small CO2 footprint (All of which is produced when they're first built), have a long life (some are still going after 100 years), and are relatively cheap to build and operate.

On the downside, their reservoirs flood large tracts of land, displacing the people and wildlife that occupied that land. So the siting of dams is often controversial and trades off the needs of the many against those of the few.

Hydro is ideal for countries with rugged highlands and abundant water sources, which can be seen from a list of nations that create most of their electric this way: Paraguay; Norway; Canada; Venezuela; Brazil; and Switzerland.

There are many hydro projects underway around the world, especially in China, so hydro will continue to be a major player, but it's not the solution for all countries, including my own. More on hydro here.

2) Tidal and Wave Power: Still in it's infancy basically. They could be major contributors in the future but that is probably some years off. More on Wave, more on Tidal.

3) Biomass: A variety of biological materials are used to generate electric. For example, burning wood alongside coal in a coal-fired power station (a process called cofiring) to reduce the overall carbon emissions; using waste from crops or manufacturing as fuel; and burning the gases given off by rotting garbage on rubbish dumps.

There are a huge range of opportunities here, whether it's growing trees and crops to be used as fuel, or recycling the mountains of waste humanity produces each year.

You've got to wonder though if there is enough potential fuel to make a difference. The only way I can see biomass making a real impact is if huge areas of land are set aside for energy crops. And that's kind of difficult to do when you need to feed a growing world population (9 billion by 2050), whilst putting a halt to deforestation.

Biomass will play a significant role in some countries (as it already does for Mauritius and Brazil, thanks to their sugar cane crops) but it may not be the 'silver bullet' some are hoping. More about biomass here.

4) Geothermal: With geothermal, we use the planet's own heat to create electricity. 24 countries currently do this, with Iceland and the Phillipines generating almost a third of their needs. Total worldwide capacity is forecast to increase by about 80% by 2015.

Any country with volcanoes and/or hydrothermal activity (e.g. geysers and hot springs) can potentially use it, and it can be scaled up to power whole cities. However, there are significant costs involved, half of which go on drilling the deep boreholes used to exploit the heat.

Geothermal is definately one to watch but, once again, it's not complete solution....yet.

According to Prof. Jefferson Tester at of Cornell University, 'Universal Geothermal' may one day  (10-15 years from now) solve all our energy problems. He believes we have the technology to make geothermal energy available almost anywhere, so long as we are willing pay for the huge initial costs of setting up the power plants.  More on universal geothermal here. More on geothermal.

5) 'Clean Coal': The coal industry is understandably concerned about it's future what with the world's governments looking to make serious reductions in their CO2 emissions. So they're trying to re-invent their product by finding ways to reduce it's carbon footprint. This all boils down to carbon capture and storage (CCS). 2 big problems there: We are probably many years away from a sufficiently useable CCS system; And any CCS system is likely to be massively expensive.

Don't get me wrong. If they did find a way to make coal low carbon, non-polluting, and affordable, I'd be amongst the first to be cheering them on. But I'm not holding my breath.

Is That It?!
Based on what I've said so far, I don't think we'd have any option but to continue relying on coal fired power stations until as late as 2030, until some revolutionary technology came along to replace them.

We just can't afford to do that. We need to start making serious reductions in CO2 emissions as soon as possible. The more we delay, the more expensive it will be to sort the mess out, and the greater the problems we'll experience from global warming.

So what's the answer? Well, there's one more option to discuss:

6) Nuclear: It's a controversial subject isn't it?

On the minus side, nuclear power stations are considered to be dangerous by some, they are a potential terrorist target, and then there's all that nuclear waste.

On the plus side, nuclear power stations can replace coal power stations one for one, nuclear is a very low carbon option, it increases a nations energy independence, and there's enough potential fuel to last out the century (and more).

Those are the headlines, the actual details are hotly debated. So here are some thoughts for you:

• Modern nuclear power stations are far safer these days. The lessons have been well and truly learnt from 3 Mile Island and Chernobyl.

• There are 440+ nuclear stations around the world at present, and another 50 or so under construction. So, like it or not, the 'genie' is already out of the bottle. We might as well make the best of it.

• A few years ago the French decided to go nuclear. Today, they have 58 reactors which generate 75% of their electric. They even export their power, bringing in billions of Euros of income. Less than 10% of their electric is from fossil fuels. The end result of their forward thinking is that they have a low carbon economy, and have complete energy security. An enviable position to be in.

I'm not saying nuclear is a perfect solution but, given the circumstances, it's the best we've got available.

The Future Of Energy Part 4: Energy Storage

In part 1 of this series, I made a case for reducing our dependance on fossil fuels as much, and as soon, as possible. In the rest of this series I'll be looking at ways this might be done.

So far I've looked at wind (part 2) and solar (part 3), and I've said that these can only ever make up 20% of our total electric supply. The reason being that they are intermittent sources (i.e. not round the clock) and you can't run a modern society on an electric supply that shuts down over-night!

So, is it possible to get round this problem? Well, it looks like the answer is (or will be) "Yes" if something called Grid Energy Storage lives up to it's promise.

The idea works like this: National power grids are set-up to meet the maximum possible demand the population can place on it. If they weren't, then there would be 'black-outs' all the time.

The trouble with this approach is that, for the majority of the time, there are power-stations sitting around idle, waiting for peak demand. Meanwhile, there will be others, the ones which can't be switched on and off at a moments notice (like coal, nuclear, solar and wind), that are sometimes generating electric with nowhere for it to go (e.g. when everyone's asleep). Crazy.

Imagine if you could store that excess electric, and release it at peak demand: You wouldn't need so many power stations doing nothing. Potentially huge cost savings.

Another benefit of energy storage would be for 'smoothing out' the supply dips in intermittent sources like wind and solar. This would effectively give you a constant supply from these sources, enabling them to make up much more than the 20% of the total electric supply I mentioned earlier.

Types of Energy Storage

There are actually many different types (See here) so I'm just going to pick out a few to show the potential:

• Batteries: It's difficult to think of batteries, even big ones, holding enough energy to be useful to a national grid, but that's exactly what they are being used for right now. The types of batteries range from relatives of the familiar lithium-ion (e.g. found in laptops) and lead acid (in cars) to the less well known sodium based, and so-called flow batteries. The most popular variety at the moment are sodium sulphur batteries but many others show promise, especially flow batteries. 

• Flywheels: These are already in use for grid power in a few cases. Flywheels involve accelerating a rotor to a very high speed to store the excess energy, then decelerating them to recover the energy.

• Molten Salt: You might remember I mentioned something called concentrated solar power (csp) in part 2 of this thread? With csp, an array of mirrors focus sunlight on a central tower creating heat. This heat is used to boil water and drive turbines. Any excess energy can be stored in reservoirs of molten salt for a number of hours until it's needed. This could have huge potential for sunnier regions like Australia, the Mediterranean, and California. It's a proven technology and it's likely to go into full commercial use very soon.

• Pumped Hydro: This is a commonly used storage technique which involves using spare energy to pump water uphill to a raised reservoir. To release the energy, you just let the water flow back down and drive a turbine. The obvious problem with this is that reservoirs aren't always possible e.g. Not enough room, or the land is too flat.

Conclusions
For me, energy storage will play a key role in our efforts to reduce carbon emissions. It will allow electric generation to be more efficient by holding onto any excess until it's needed; permit solar and wind power to be bigger players in generating electric; and, for transport, smaller, cheaper, lighter batteries will revolutionise electric cars.

And that's just the tip of the iceberg.

But energy storage is still in it's infancy and it may be a decade or more away from making a real impact. So what do we do in the meantime? Well, for a start, keep adding to the wind turbines and solar power stations as fast as possible. It's going to take a while for most countries to reach their 20% thresholds anyway. By then, energy storage may be in the position to take off.

My concern though is: What happens if, for some reason, energy storage doesn't take off?

I look at a possible answer in the next part of this series.

More on energy storage.

The Future Of Energy Part 3: Solar Power

In part 1 of this series, I made a case for reducing our dependance on fossil fuels as much, and as soon, as possible. In the rest of this series I'll be looking at ways this might be done.

In part 2 I looked at wind power, this time round I'll be talking about the role solar power might play.....



Current State Of Play
Solar energy is a very fast moving area of technology, with new developments coming through all the time. However, there are, broadly speaking, 2 ways solar is used to generate electric: Photovoltaic (PV) e.g. solar panels; and concentrated solar power (csp) which typically involves an array of tracking mirrors (heliostats) that concentrate light on a central tower to boil water and drive turbines (See photo).

Concentrated Solar Power

CSP has been around since the 1980s. The largest power station is currently in Mojave desert, California (354MW). The world's CSP power stations are largely split between the US and Spain. These 'Solar power towers' are more cost effective than PV, offer higher efficiency and better energy storage capability (Storage will be the subject of a later post).

Germany has the largest PV station (80+ MW) in the world with Canada close behind. Other leaders are Spain, Portugal and Czech.

PV makes up less than 1% of the world's energy. There are many competing technologies but, as yet, no clear winner. This fierce competition is leading to rapid improvements in the efficiency of solar cells and driving down costs.

Home PV: Germany led in this until recently with 4,150 MW installed (Thanks to government incentives). Spain then took over, using a similar scheme, and now have 45% of the world's domestic PV. France, Italy, South Korea and the US are also seeing rapid growth. Globally, the market could reach 16GW this year. As a result of all this, PV production has grown by an average of 40% every year since 2000 and seems likely to go on growing strongly.



Pros and Cons
The pros and cons are very similar to those for wind: Solar energy is plentiful, clean, renewable, available almost everywhere, and creates no greenhouse gases.

Like wind, it is currently more expensive than the other, established methods of generating electric. But, of course, coal powered stations were also costly when they first appeared. This is what happens with all new technology: It starts out very expensive and gets cheaper as time goes by.

The real drawback is that solar energy is intermittent e.g. It dips when there's cloud cover and stops altogether over night. So there need to be other, more constant, energy sources available to fill the gap. Fortunately, grid operators are used to matching supply to demand, so it's no big deal at present. But, as intermittent renewables like solar and wind reach 20% of the overall total, it'll begin to get trickier. That's still a few years away though and there are likely to be a number of solutions available when that day finally comes.


The Future
It's been worked out that if just a small percentage of the planet's deserts were used for generating solar power, it would be enough to provide all the world's electric for the foreseeable future. Earlier this year a plan was presented to Australia by a group of scientists, engineers, and economists that offered them a 100% renewable energy economy by 2020 (See here) and that included a lot of CSP. So there's huge potential for solar power.

However, fulfilling that potential will depend a lot on the willingness of governments, both national and local, to make it happen. Some countries, like Germany and Spain, are going all-out for renewables generally, whilst others seem to be dragging their feet.

Solar Updraft Tower

Keeping that in mind, home PV seems likely to continue growing rapidly if governments continue to offer incentives. CSP is a revolution waiting to happen in the tropics and sub-tropics.

Other stuff waiting to take off includes solar paint (which promises solar at a third of the usual cost), solar thin film (which offers such applications as solar windows), concentrated PV which concentrates energy on a single cell for cheaper PV, and, my personal favourite, solar updraft towers which combines 3 well known effects to produce a really novel design.

All very exciting but will it actually happen.....?

-- oOo -- 

More about solar power here.

More about CSP here.

The Future Of Energy Part 2: Wind Power

In part 1 of this series, I made a case for reducing our dependance on fossil fuels as much, and as soon, as possible. In the rest of this series I'll be looking at ways this might be done.

This time round I'll be talking about the role wind power might play.....

Current State Of Play
By the end of 2009, wind produced 2% of the world's electric, double what it was just 3 years earlier.

It provided 20% of the electricity in Denmark, 14% in Ireland and Portugal, 11% in Spain,  8% in Germany, 3% in the UK (with plans to have 15% by 2020), and 2.4% in the U.S.

Worldwide the 5 biggest producers are, in descending order, the United States, China, Germany, Spain, and India.

Ironically, Texas, the oil state, is also the U.S.'s leading state for wind power. It has more than double the UK's output, and if it were a country, it would rank 6th in the world!

Currently, the world's biggest offshore windfarm is off Kent, UK, with 100 turbines. This will soon be dwarfed by 'farms being built and planned elsewhere.

Offshore windfarms are costlier to build than land based, but the extra cost is offset by an improved supply.

Worldwide, the rate of growth in wind power is accelerating with dozens of countries investing heavily in the technology. However, because fossil fuel demand is also growing, wind may only provide 8% of all electric by 2018.


Pros and Cons
Wind energy is plentiful, clean, renewable, available almost everywhere, and creates no greenhouse gases.

However, it is currently more expensive than other, more established ways of generating electric. Well, it is new technology, and like all new tech, the cost is still coming down steadily. So the comparison isn't particularly fair.

Another issue is that you don't have control of the supply: The wind may drop off when you need it most, or be blowing a gale when you don't want it. But electric grid operators are used to meeting varying demand for electric on a round-the-clock basis. So they don't consider varying supply to be a problem, as long as it's part of a balanced mix of sources and wind makes up no more than 20% of the overall supply.


The Future
As I've said, costs are coming down steadily and wind will become increasingly competitive compared to the established technologies. I'd hope that this will mean that wind will be contributing more than the forecasted 8% of the world's electric by 2018.

However, there's that 20% upper limit to consider - Since wind energy is so intermittent, it may be uneconomical to manage beyond this point - So wind could only ever be part of the overall solution.

Looking further into the future, high altitude wind power (HAWP) shows promise. It is based on the fact that, the higher you go, the stronger, steadier and more persistent the wind gets. Traditional turbines wouldn't be able to exploit this, but things like tethered kites and balloons could. That might sound a bit....low tech, but there's some serious money chasing this one and, it's claimed, HAWP can out perform the current generation of turbines, both in terms of cost and output.

Early MARS Prototype From Mageen

There are several companies developing HAWP, including Joby, Mageen, Drachen, KiteGens, and Makani. Most seem to be at the concept or prototyping stage but Mageen are looking to roll out their MARS rotary balloon system to remote rural villages in India next year. Commercial applications still seem to be a few years away but we appear to be seeing the beginnings of a revolution.

                                  -- oOo --

More information about wind power here.

More about HAWP here.

The Future Of Energy Part 1: Fossil Fuels

We are hooked on fossil fuels.

We currently consume around 4 billion tonnes of coal, and 3000 billion cubic metres of natural gas annually, and 86 million barrels of oil per day. The result is around 30 billion tonnes of CO2 emissions per year.

Furthermore, demand for all 3 is predicted to increase by around 2% per year until 2030. So, in the absence of a worldwide climate change agreement, carbon emissions are set to increase by about 40% over the next 2 decades.

Of course, all this assumes supply continues to meet demand. And, in the case of oil and gas, this is by no means certain. If demand for oil did outstrip supply, it would be disastrous for the world economy because we are completely dependant on a cheap, plentiful supply.

Then there's the matter of energy security. Countries need to protect themselves from sudden price hikes caused by natural disaster (e.g. Hurrican Katrina), political instability (e.g. in South America, Middle-East or Russia), and profiteering from the likes of OPEC.

Finally, there's the looming problem of climate change. The world is getting warmer (See here) and, whether you believe we're the cause or not, adding these vast quatities of known greenhouse gases to atmosphere can't be helping matters.

So, for all these reasons, we need to urgently increase our efforts to find replacements and get them scaled up in time to meet those challenges.

We also need to stop subsidising oil and coal, and improve energy efficiency.

The ultimate aim is for the demand curve for fossil fuels to first level off then fall steadily to more acceptable levels. The sooner we can do that, the better.