Weekly conversations - Tesla

Over the last week, renewable energy on its own hasn’t been brought up much in conversation, but a connection to renewables has, in the form of Tesla, Elon Musk’s brainchild. Now whilst this company originally specialised in high tech electric cars, the company has used its success in this field to push the sustainable living to the next stage. Powerwall battery systems have been linked with solar panels and even solar roof tiles, which allows storage of electricity generated, so that it can be used at night for example. This has been shown to be highly effective in Australian homes, at a similar cost to paying for fossil fuel generated electricity – surely a win-win.

Tesla is precisely what the developed world needs to push forward renewable technologies. They have created products which as technologically advanced, whilst also generating demand from ‘normal’ households. Typically eco-homes and solar panels have been restricted to eco-warriors or those who benefit from government grants, but this allows it to be opened to the market, for all to access, at an affordable price – something which will become even more apparent with the release of the ‘Model 3’ car, an affordable electric saloon.

By combining environmental benefits with state of the art technology, such as autonomous driving, Tesla offers consumers more than just peace of mind that they are more environmentally friendly, they also provide great products, at reasonable prices. A lot of the renewable methods and innovations discussed have been in very preliminary stages, and have significant barriers to overcome before they can be applied, but Tesla already has these products available now, and the products are extremely popular. Perhaps the market approach, rather than the infrastructure and government-side approach to renewable energy, is the way forward. It has certainly gained enough traction.

Hydroelectric power

As with my blog post on geothermal energy, hydroelectric power falls into the category of ‘effective but less widespread’ renewable energy sources. Despite this, hydro power has existed for over 100 years, which means that technology has matured and the efficiency of energy production has increased greatly, at ever lower costs. This means that hydro power, when effectively applied can produce huge amounts of electricity, in a sustainable manner – China’s hydroelectric power plants supply power to more than half of the country, reducing the reliance on fossil fuels. However, dams are not perfectly environmentally friendly. Requiring flooding of large areas of land, and huge construction projects, dams may seem like a brutal method of renewable energy production. The environmental effects stretch beyond just flooding and aesthetics however, with reservoir sediment building up over time due to soil erosion and human induced changes. This sediment can block up turbines and intake pipes, reducing its efficiency over time, and can become a secondary pollution to the environment if removed and not properly managed. This can be often overlooked in the construction of dams, and harms the renewable nature of the resource from both a production, and environmentally friendly standpoint.

As a result, work has been done finding a way to use this sediment, namely in construction. The Design for Six Sigma plan describes a method of turning masonry waste and reservoir sediment into fully useable bricks over a period of around a month. This in turn solves a multitude of environmental issues. Less waste is produced by the construction industry, reducing the high carbon footprint of cement production. Similarly, ecosystems are protected from the dumping of reservoir sediment. These two factors link together to create a much more sustainable method of development through the major sectors of energy production and construction. I found this method particularly interesting, as it seems to offer a win-win scenario for so many different actors, that is rare to find in the renewable energy debates, and it demonstrates how advancements in green technology can bring benefits to other, previously disconnected industries.

Although hydro power has been around for over a century, there is still scope for drastic changes to how we produce energy using water. For example, this study poses a new design of generator which could be applied to streams and smaller waterbodies without the need for damming. The study, undertaken in Japan notes that its application could produce millions of killowatts of electricity by adding the generators to small and medium sized waterbodies. The generator basically involves the oscillation of a vertical wing submerged in water, which can produce energy using a clever generator and maths that went so far over my head that it may has well have been another language. Despite this, the method does not require any part of the generator to be submerged other than the vertical wing, and as a result could be less intrusive on waterbodies, and may have a longer lifespan due to no need for water sealing. The method proposed is also reasonably efficient, at 32-37% efficiency, which is very reasonable for such a new method of renewable electricity generation. Obviously this is very much in a preliminary phase, and it is unlikely to be applied for a number of years, but it does demonstrate how even in well used and researched methods of renewable energy production, new ideas can be created that increase the utility of the renewable resource.

The final area I wanted to cover was looking at what currently exists in hydro power. Whilst it is useful to have an idea of future innovations in renewable energy, one must not lose sight of what the present situation is, and how effective our methods are. The Belo Monte dam, in Brazil aims to tackle one of the richest hydropower resources in the world, being set within the Amazon basin. However, as stated earlier, construction of traditional dams requires flooding of large areas, which in the case of Belo Monte, is 516km² of river, forest, crops and urban areas. This is clearly problematic for the Amazon rainforest, which has been subject to huge deforestation already. Therefore the impacts of the dams construction must be understood, both from a social and environmental perspective. Tropical rainforests hold the highest biodiversity indexes of any biome, and so flooding large swathes of land has a huge effect on species within the rainforest. This raises the question of conservation versus renewable energy, with both aiming to mitigate humanity’s impact on the planet. Understandably, the dam has come under a lot of flak for these impacts, and many see the dam as unnecessary considering the range of other renewable energy resources Brazil has to offer, even posing smaller dams as a less damaging, more efficient alternative. Indeed Berchin et al consider Brazil to be obsessed with large scale projects which are not as effective as pushing solar and wind power forward in the country.

The debates surrounding hydro power, and in particular dams such as the Belo Monte, make an interesting distinction between clean energy, which is carbon neutral, and sustainable energy. Overreliance on any one energy method seems to flag up negative consequences in one form or another, and hydroelectricity is a key culprit of this. With such drastic landscape changes required to put in effective hydro power plants, it is hard to see the electricity produced as sustainable. Yet with high yields, and a large research base, we should not write off hydro power, but see it as yet another weapon in the fight against fossil fuels and climate change. With careful planning, and innovations such as the oscillating wings, hydroelectricity is an invaluable resource, and will only increase in effectiveness in the future.

Geothermal energy

Up to now, a lot of the focus of the blog has been on wind and solar power, the two main sources of renewable energy in the world. However, in certain locations geothermal power can be just as important. Geothermal energy relies on the heat of the Earth to generate electricity, often through the heating of water in pipes which pass through the hot rock deep underground. This is more applicable in areas of high volcanic activity, such as Iceland, where the rock only a short distance underground becomes heated. However, it is not limited as much as previously thought, and 10,715 MWe were produced in 2010. With the extra funding put into the renewable sector, and a greater need for carbon neutral energy sources, novel applications of geothermal energy have become apparent. In my research, the wealth of recent information concerning these new innovations warranted a separate blog post in the search for a solution to our energy crisis, and the opportunities that geothermal energy can offer only adds to the arsenal of energy sources available in the modern world of energy production.

The first relatively new method of geothermal energy production is its application in shallow aquifers. This involves the use of the subsurface to extract or inject heat through either groundwater pumps or pumping water underground for heating. This has been increasingly used in the last 15 years, with many more plants using these methods. However, there are a certain number of obstacles in place before these methods are deemed a sustainable energy production method. For example, the use of groundwater in energy production influences local water temperatures, either increasing or decreasing them depending on the method of geothermal use. Therefore in order to be sustainable, the production of energy must not cause damage to groundwater quality, or the ecology supported by the groundwater, which includes the water level, as well as the chemical composition. However due to the recent application of the method, the effects of shallow geothermal power are not well understood, particularly long term environmental impacts. If better understood though, the side effects of geothermal power could result in larger benefits. For example, heat extraction from groundwater can lead to a fall in temperature in the aquifer, which can combat the anthropogenic heating of aquifers in urban areas. So in cities, perhaps geothermal power would be even more beneficial for the environment beyond reduced emissions. In order to use this method effectively, there must be a safeguarding system against any negative impact on the environment, which is suggested to be possible through the use of a legal framework underpinning the use of geothermal energy and its sustainable use.

The second novel method of geothermal power use is rather more metaphorical – using abandoned oil and gas wells as a way of getting geothermal energy. In essence, this offers a way of using infrastructure from fossil fuel production in a renewable world, as a direct replacement of the old carbon-based methods. Many oil and gas wells are now abandoned, having extracted all of the fuel reserves from them, and a large number of these exist in China, having fed the massive growth of the nation. With retrofitting of these wells, it has been shown in experiments that heat can be extracted from the wells through the water flow between the bedrock, with the amount of energy determined by the flow rate of the water, and the temperature of the rocks. Even extensive use of the well for geothermal power only causes a temperature drop of 2°C over a decade. In addition, as these wells are typically far from major settlements, they can also be used for electricity generation effectively, through the use of steam turbines, which increases the utility of refitting these wells. In ideal scenarios, this form of geothermal power can bring over $36,000 each year from the electricity produced. Due to the large number of wells available in China, this could be a major method of converting energy supply to renewables for the nation, which could have huge effects on global emissions. However, it remains to be seen how massive scale use of this method effects the environment and water levels, for example.

The final use of geothermal power is more of a complementary method, which could exaggerate the renewable nature of its production. This method uses CO2 as the fluid which is injected into the subsurface, instead of water. There are a number of advantages to this approach, namely the higher mobility of CO2 in comparison to water. This allows it to exchange heat more effectively at the desired temperature and pressures that have been posed. Theoretically this could lead to up to 5x more heat energy able to be extracted, compared to engineered geothermal systems. As well as making existing power plants more efficient, this could allow geothermal electricity production in more areas, due to the greater yield. Furthermore, the CO2 injected into the bedrock slowly sequestered into the ground, leading to a net reduction in CO2 levels – making this method act as both a geoengineering and energy production method.

These technological advances show how geothermal energy could become a much larger player in the renewable sector in the future, and its flexibility if combined with CO2 use and abandoned well schemes could take it from only worthwhile in a select few localities, to a much more widespread application. It is this kind of innovation which could really change the renewable sector, and with so many different novel methods coming out of the last 5 years, the future of geothermal energy is looking pretty hot indeed.

Green energy is ruined?

I recently saw this article shared on Facebook with a huge amount of likes and shares. The basic premise of the argument is that green energy in Europe is a scam and is emitting more than fossil fuel equivalents. This clearly seems problematic from the outset, and reading through this made me quite unsure about the place of social media in green energy debates. The ‘clickbait’ nature of the title fails to show the bigger picture. ‘Europe’s green energy policy is a disaster for the environment’ is something of an overstatement, as the actual article only talks about biomass burning, and glazes over the swathes of ‘good’ renewable energy being invested in, especially in western Europe and Scandinavia.

Now onto the meat and gravy of the article. The pivotal statement is that burning wood releases carbon into the atmosphere, at a greater level than the amount of carbon sequestered by the trees over their lifecycle. Whilst this may be true for wood, some biomass is produced via non-wood products, and has a much more carbon-neutral production. As for the wood itself, this comes into an interesting distinction – wood from afforestation has been found to be low emitting, lower than the emissions of fossil fuels. Similarly, waste wood, salvage wood and ‘pre-commercial thinnings’ are also low emitting. So the only types of wood that are high emitting are sawn wood, coarse dead wood and tree stumps. The article fails to attempt to find out how much of the latter group is being used for biomass production, and this could undermine the entire argument. Now, I’m happy to be proven wrong with sufficient evidence but it seems to me at the moment that New Scientist is clutching at straws to trip up Europe’s green energy policy for the sake of a shocking headline. This is particularly evident through the sheer number of people sharing and responding to the article with shock on social media, and this engrains a lack of trust in environmental government practices which (may) be unjustified. With so many delegates and climate scientists working on policies to reduce emissions, I cannot see how something that is made out to be so shocking, has been overlooked. The net emissions of bio power are likely lower than fossil fuel equivalents, and whilst some aspects of the burning may be high emitting, these probably do not take up the majority of the biomass generation.

If for some reason the biomass issue has been occurring, then official documents of the European Commission do acknowledge the high emissions of certain aspects of bio power, and so I am sure steps are being taken to minimise the amount of high emission bio power generation.

However, I am confident that there is no ‘grand scam’ taking place, and with the efforts of so many countries building wind and solar farms, and countries like Iceland already producing most of their energy sustainably, I believe that our governments do truly want to reduce emissions and mitigate the effects of climate change. I have witnessed the positive outlook on European energy policies through my blog and research for it, and if the future of green power was not looking so good, I would probably cut this article some more slack – but this is not the case. Sadly, all it takes is a few articles such as these to go viral, and the hard work and huge investments of so many are overlooked.

Developing nations and renewable energy

Last week as part of my studies, I took part in a mock COP21 debate, which saw us become delegates from each country, who were to come together and decide on emissions cuts to mitigate anthropogenic climate change. The debates ended up highlighting some interesting things – one of which being that developing nations seemingly held little ability to cut their own emissions, mainly limited by funding.

In reality, this is avoided through overseas investment and in recent weeks there have been some major advancements in renewable energy projects funded through foreign investment. For example, Skytron energy has just been commissioned to supervise the ‘Oriana’ solar power plant in Puerto Rico which has been active since September. This plant provides power for 12,000 homes and has a net carbon displacement of 95,000 tons of CO2 per year. This shows that despite having limited funding, developing nations can join the push for renewable energy.

Morocco similarly has had a huge amount of investment from overseas into renewable energy. Around $3.9bn has been invested into the Ouarzazate solar complex which has come from German investment bank KfW, the World Bank and European Investment Bank. This has led to the creation of the 160MW plant, which is being expanded to a total 350MW added to the national grid. In combination with investment in wind power of a further 850MW, this will help to reach Morocco’s aim for 52% renewable electricity generation by 2030.

These plans show that the developing world is not separate to renewable energy, but can use it to develop as exemplar countries with high levels of renewable energy generation. Indeed, Morocco’s wind power plants expect to produce electricity at $0.03 per kWh, which will also help to develop the country through lower energy prices. Perhaps then the argument to allow developing nations to emit as much as they like, due to their lower ability to adapt to new energy systems and their lack of responsibility for past emissions, can be revoked. Many developing nations have land ripe for providing renewable energy, with countries like Morocco prime examples of this – with high solar insolation aiding the implementation of solar power.

As suggested in a previous blog post, one solution to the renewable energy debates is to create a global network of renewable energy, using each energy source in its most efficient location. This in a sense is already being applied with foreign investment funding projects such as those discussed, and perhaps one way for developing nations to pay for these power plants is to provide energy to the funding country, once enough energy is produced for the hosting country. Obviously this is a long way off, but it offers a way for developing nations to hold greater power in global debates such as those at the COP21 meeting.