Renewable Technology Innovation

Whilst writing this blog, I have looked at five most commonly used renewable resources and have seen the significant research and development going into each area, with wind, solar and biofuels seeming to have some of the most rapid and exciting technological advances.

So I now turn to some of the more undeveloped and comparatively unestablished technologies that are still in their infancy. Renewable energy is an exciting area full of innovation and possibilities, but in this post, I intend to highlight two technologies that really caught my attention. Both have already been piloted and deployed on a small scale, receiving significant interest and investment.

1. Pavegen Tiles 

These tiles capture the kinetic energy transferred to the ground when an individual is walking or running. 7 watts of energy can be generated from one footstep, which can then be stored by batteries and used as a power source for lighting cities.

These tiles have already been deployed in a number of locations, including the 2013 Paris Marathon, Heathrow airport and Westfield shopping centre in Australia where the energy was used to power their Christmas trees lighting. Finally, these tiles were installed as astroturf, laid in a football pitch in a favela within Rio de Janeiro. The energy produced by the local children playing football is used to light the local area.

It such an exciting technology and has received enormous support. The company recently welcomed the former executive of Apple to its advisory board and the increasing popularity resulted in massive investment resulting from a crowdfunding campaign in 2013. This campaign saw overfunding of 275%. With such a successful advisory team behind this company and the finances available to them, it is highly likely that we will see this technology being deployed at a rapid global scale in coming years.

Pavegen Tile Installation at the Paris Marathon, 2013
Source: earthtechling.com

2. Ocean Thermal Energy Conversion

The second innovative technology is ocean thermal energy conversion. This uses the temperature gradient between cool deep ocean waters and relatively warm surface waters to rotate a turbine which then produces electricity. Although the current model is relatively inefficient (currently at 1-3%), there is significant research and development going into this area.

There has been great interest in piloting this thermal conversion technology, with Lockheed Martin and Reignwood signing a contract in 2013 to develop a 10 MW Ocean Thermal Energy Conversion Power Plant off the cost of Southern China. Hawaii also installed a 105 kW plant off its coastline early last year. Hopefully more of these projects will be seen once improvements in the efficiency and design are complete.

With the signing of the COP21 agreement and the pledges made by nations to significantly reduce their carbon emissions, we are likely to see increased investment going into developing and piloting new renewable technologies. I have already outlined the huge funding algal biofuels projects have received in the US, and hopefully we will see this type of investment available for other projects that are currently in their infancy, ready to be improved and piloted.

Tidal Power

Although it isn't considered one of the main renewable energy sources, tidal power still has huge potential in the fight to replace fossil fuels with green energy alternatives.

One of the key benefits of tidal power, as discussed by Denny (2009), is the predictability of wave energy. It is a far more reliable source than both wind or solar, however there still limitations, as energy production can only occur when the tide is flowing in or out. 

The largest tidal power stations in the world are the Sihwa Lake Tidal Power Station in South Korea, closely followed by the Barrage de la Rance in France. Both are tidal barrages, dam-like structures containing turbines which capture the waters energy as it moves in and out of the barrage during high and low tides. 

Barrage de la Rance, Brittany, France
Source: Britannica.com 

One highly controversial tidal barrage proposal is the Severn Estuary Barrage. There has been much concern surrounding its viability, both environmentally and economically, and as a result, there are still no formal plans for its construction. There have, however, been developments in its design, with a new tidal fence proposal which would have fewer environmental consequences as it can be placed in shallower, slow moving water, allowing migratory fish to move up and downstream and continuing to expose mud flats during low tide. A 14km stretch of this tidal fencing would result in circa 600MW of energy being produced at peak times. 

Many claim however, that barrages are not the way forward for tidal energy, and the potential of this resource can only truly be exploited using underwater turbines which capture tidal energy from the currents. O'Rourke et al. (2009), state that tidal turbines are not currently the most economic option and are still relatively underdeveloped, but despite this, it is one of the most popular methods, seeing huge investment in developing the technology. In time, it is likely to improve in efficiency, decrease in cost, and become more environmentally friendly as technology advances. An underwater tidal turbine project is currently underway off the north coast of Scotland, with an initial 86MW development currently under construction. This will potentially be followed by a second 212MW development in the coming years.

There seems to be a significant amount of development in tidal power technology, and although there are limitations on availability of suitable sites that can exploit this resource, it is an interesting concept. If significant amounts of energy can be produced by one of these developments, it is certainly an area worth investing in.

Algae: the next biofuel?

During my research into the potential of biofuels, much of the literature focused on the substantial investment going into developing algal biofuel technology. The United States are at the forefront of much of this research, with the US Department of Energy currently investing $18 million in six new innovative projects.

A study by Lui et al. (2013), suggested that algal biofuel could significantly reduce CO2 emissions, with this fuel source producing fewer greenhouse gases than corn produced biofuel. There is also the benefit of saving space as algae produces 12x more biofuel per acre than crops.

Cultivation of Algae Biofuel
Source: Arizona State University

The issue at present is the cost of this energy source. Algae requires more CO2 for growth than is available in the atmosphere, therefore bottled CO2 is required renders the production process extremely expensive.

However, due to the huge investment in this area, there is a great deal of research taking place, aiming not only to make production more economically viable, but also to find different production methods. One new development is the discovery of a species containing an enzyme allowing it to exist in high concentrations of nitrous oxide. This opens up the possibility of feeding this algae  power plants emissions because their ability to metabolise nitrous oxide stops the emissions from being toxic and they can benefit from the high concentrations of CO2. This is still in early stages of development, but it is one demonstration of the innovate research occurring in this area.

Algal biofuel is certainly an exciting area of research and hopefully over the next few years we will witness some of these exciting discoveries becoming advanced enough to bring to market.

Biomass Energy Controversy

There is a lot of contention over the sustainability of biomass energy. Some argue that this is a 'carbon neutral' energy source as the uptake of CO2 during regrowth of new biological material equals the CO2 released through the burning of biomass. However, the biosphere is a complex system, therefore, this could be seen as an over-simplified view. 

Abbasi & Abbasi (2009) argue that although biomass production is carbon neutral, it not nutrient neutral, with large scale biomass energy production disrupting the nitrogen cycle, resulting in eutrophication. The study also highlights the large quantity of water required for biomass growth. In Arizona, for example, the rate of groundwater used for corn production is ten times that of aquifer recharge. 

Another key issue, is the replacement of tropical rainforests with monoculture plantations for the energy industry. Danielsen et al., (2008) highlights the importance of tropical regions for carbon sequestration; this is greatly reduced when replaced by monoculture plantations. These areas are also biodiversity hotspots and the removal of natural vegetation results in an immediate loss of flora, fauna and habitats.  As a result, biomass energy production in these regions is unsustainable. Not only is carbon released into the atmosphere through rainforest removal, the plantations are less effective carbon sinks, resulting in a net increase in atmospheric CO2. The study states that preventing topical deforestation is likely to be a better method of combating climate change than biofuel use.

Rainforest clearing for Palm Oil Plantation in Cameroon
Source: Greenpeace

Sulphur oxide, nitrogen oxide and black carbon emissions are another significant impact of biomass burning. Galdos et al., (2013) outlines the environmental and social issues of Brazilian sugar cane ethanol production. The process involves pre-harvest burning of unwanted biomass which releases huge quantities of black carbon. This is not only hazardous to human health, it also absorbs long-wave radiation which has a net warming effect on the Earth. However, the study did state that improving mechanisation of this process is reducing the need for pre-harvest burning. 

Hill et al., (2006) looked at the benefits of biomass, in particular biofuels, finding that biofuel produced by waste and on marginal land is more environmentally beneficial than food-based biofuels. The study also suggests that biodiesel uses less nitrogen, phosphorus and pesticides and produces fewer pollutants per net energy gain than bioethanol. 

There are also political and economic benefits of biomass energy, including reduced dependence on other nations and the potential for biomass energy to be cheaper than fossil fuels. But can't this be said for other the renewable energy options that appear to be more sustainable? 

To conclude...

After my research, I still don't see biomass as a sustainable option, especially when produced in tropical regions where the negative environmental impacts vastly outweigh the benefits. For electricity and heating production, there are more sustainable options, however there is one area where I do see the benefit and that is biofuel. 

Transportation is responsible for circa 13.5% of greenhouse emissions, however, it is difficult to rapidly change this sector due to the high cost of replacing vehicles with green alternatives. The technology behind electric and hydrogen vehicles is now well developed, but the cost is still a barrier. Biofuel, particularly biodiesel, could be a more sustainable option in the short to mid term until there are technological improvements and a price decrease in green transport alternatives.In the longer-term however, focus should be on other more sustainable transport alternatives. 

Moving on to Biomass...

Up until now, I have been researching renewable energy sources that I fully support. My research has highlighted a number of environmental and social issues associated with each one, although research and technology is likely to reduce these disadvantages with time. Furthermore, the negatives are small in comparison to the global impacts of fossil fuel use.

That is why I have saved biofuels until last. At present, my knowledge is limited, but I am not a huge advocate of this energy source because I don't see it as a sustainable resource. 

I understand the principle, that carbon emitted through biomass energy is then reabsorbed by new plants growth. This is seen as a relatively fast process compared to the millions of years for carbon to be stored as fossil fuels; however, carbon sequestration by plants still takes decades and if the plants aren't replaced at the rate in which they are used, this resource stops being sustainable.

In my next few posts, I will be looking at both the positives and negatives of biofuels, in order to develop a more informed opinion and conclude whether it should be increasingly utilised in the fight against climate change.

Harvesting of Sugarcane for Biofuel in Brazil
Source: Britannica

To provide some background, biomass is an organic material that has gained and stored the sun's energy during its lifetime through the process of photosynthesis. Humans are able to utilise this energy through the decay, burning or fermentation of this organic material. It is considered a renewable energy source as there is no long-term supply limitations as plants can be relatively easily and quickly replaced. 

Biomass energy can come from a number of sources; these include:
1. Wood: Today, this is still the largest source of biomass energy. By burning chips, logs and sawdust, wood is typically used in the production of heat energy
2. Biogas: The gases, (typically methane and carbon dioxide), produced through the breakdown of organic material, sewage or manure. These can be used as a fuel for heating or transport purposes
3. Fermentation: Through this process, two types of biofuel can be produced, bioethanol and biodiesel. The former can be produced through fermentation of sugar using beet or sugar cane and the latter being produced using vegetable or animal fats. Both can be used as fuel for heating and transport

In 2014, biofuel production increased by 7.4%. The largest producers were the United States, and Brazil with 42.5% and 23.5% of the global 2014 share, respectively. In their 2012 strategy, the UK government highlighted their support of sustainable biomass energy. It was outlined that its versatile methods of utilisation, across all three energy sectors (electricity, heat and transport), makes it a beneficial resource. 

There still remains a lot for me to learn about this resource and my next few posts will consider both the benefits and issues of biomass energy. I will be highlighting some of the key studies I come across which will no doubt challenge my opinions.

COP21 ends. Climate Change action begins

After two weeks of intense negotiations, COP21 draws to a close. Over this period, something truly historical has been achieved. Today, 12th December 2015, an agreement was signed in Paris, committing all nations to limiting global warming to 2°C through the reduction of greenhouse gas emissions.

As a result of this summit, there has been amplified global interest in Climate Change. This has culminated in the signing of the first universal agreement on global warming which contains both legally binding and voluntary aspects. This landmark achievement doesn't simply reflect the hard work from all parties involved in the summit, it represents decades of dedication from scientists, campaigners and policy makers who have fought to highlight the significance of anthropogenic climate change and its impacts.

In an interview with the Guardian, climate scientist and former Vice Chair of the IPCC, Jean-Pascal van Ypersele said that this agreement was "a recognition that the science is solid and that everyone is aware of the urgency of tackling the issue".

The moment it happened: Christiana Figures, Ban Ki Moon, Laurent Fabius, President Hollande
Source: Francois Guillot, Getty Images

Some of the key messages in the agreement are:

1. Limiting the global mean temperature rise to "well below" 2°C, with ambition to limit this further to 1.5°C. Although many vulnerable nations were pushing for an absolute 1.5°C limit, having this number in the agreement is a far greater achievement than many could have imagined when the summit commenced 

2. Developed countries are to continue financial assistance for developing nations, to enable them to mitigate and adapt to the impacts of climate change- a goal of $100 billion has been outlined in the agreement

3. Greenhouse gas emissions should peak as soon as possible and by the second half of the century, these emissions should be balanced with carbon sinks

4. A review of the pledges should occur every five years with each one a progression on the last

Although this is the end of COP21, it is just the beginning of the global fight to cut greenhouse gas emissions and limit climate change. Today we have witnessed the signing of a landmark agreement, however there is much more that must be done over the coming years, with the need for pledges to become more ambitious. Whilst this agreement is not perfect, it demonstrates the unity of nearly 200 nations in acknowledging the importance and urgency of tackling climate change. Most crucially, it puts in place the first serious global commitment on what will be a long journey to stabilising anthropogenic impacts on the world's climate.

Geothermal: Public Perception

One key method for production of geothermal energy is the Enhanced Geothermal Systems (EGS) process, whereby fluid is inserted into fractures in the earth and heated by hot rock below the surface. This heated fluid is then used for electricity generation. Issues do however arise through the forcing of fluid into these weaknesses; new fractures can occur and existing ones can be widened which can result in induced seismicity. This issue has long been acknowledged, with Mock et al. (1997) stating that the magnitude of induced seismicity due to extraction is typically very small and does not compare to the high frequency of earthquakes that are typical for these active tectonic regions. 

However, after a series of earthquakes occurred in Basel, Switzerland in 2006 as a result of geothermal drilling, the subject has received a great deal of public concern, research and media attention. The strongest earthquake from this incident, a 3.4 magnitude earthquake, caused damage to property costing over $9 million. 

Giardino (2009) stated that the probability of creating earthquakes significant enough to be noticed on the surface is small. However, the risks still must still be considered and thorough risk analysis should be conducted before a project commences. Research into the public perception of geothermal power station safety was conducted by Carr-Cornish & Romansch (2014), who found that fewer people rejected proposals for geothermal projects when increased information and transparency were provided; however, most were happier with projects located away from settlements. This produces a key issue: an efficient geothermal plant not only generates electricity, it also provides heated water for homes and businesses, but this requires the plant to be located close to existing communities.

Mammoth Pacific Geothermal Power Station, California
Source: blm.gov

My last post outlined the huge potential of geothermal energy, however this post has looked at the risks and public concern surrounding the EGS method. Concern over induced seismicity has been heightened in a number of countries as a result of fracking, with Ellsworth (2013) stating that the increased frequency of small earthquakes in the United States, resulting from industrial activity, has raised public concern. As a result, the increased risk of these events combined with public concern could lead to difficulty gaining acceptance for new projects, despite these areas being naturally prone to earthquakes. 

As a result, not only do these new projects require careful assessment and thorough planning, they also need to account for heightened concern over industrially induced seismic activity that could play a part in the public perception of EGS. To prevent misunderstanding and backlash, strong communication and transparency will be required whilst planning future sites and proposals to ensure that this renewable resource reaches its full potential in a safe manner without harm or concern to local communities. 

Geothermal's Geographical Limitations

My previous posts have focused on solar power; a widely available, under-utilised resource with small geographical limitations but supply constrained by hours of sunlight. In stark contrast, geothermal energy has large geographical limitations, far smaller availability but continuous accessibility. Therefore, I wanted to focus on this resource in my next few posts to see how feasible large scale deployment is.

Geothermal energy is the utilisation of the Earth's internal heat energy in order to produce electricity for anthropogenic use. This internal heat can either come from radioactive decay within the Earth's crust, or from the energy resulting from the Earth's formation.

In some areas, natural water sources are heated by the transfer of this thermal energy below the Earth's surface. In areas with very hot subsurface rock, but limited natural groundwater sources, water can be actively pumped below the surface and then returned to a power station. In both cases, the hot water can be captured and the release of steam is used to drive turbines, which produce electricity for commercial use.

The Workings of a Geothermal Power Station
Source: bbc.co.uk

Iceland is well known for its abundant geothermal resources which are available due to the country's geographical location on the Mid-Atlantic Ridge. It is one of the most active tectonic locations on Earth due to the spreading of the North American and Eurasian plates on which it sits. These plates are currently moving apart at a rate of circa 2cm a year.

Ragnarsson (2013) outlined the nations significant use of renewables, with 87% of energy in 2013 provided by their own clean resources; 69.2% of this being geothermal energy and 17.6% coming from hydropower. The research outlines the transition to renewable energy that took place in the 1970's after the huge global increase in oil prices; today, 90% of the nations heating is provided by geothermal resources.

The United States is also produces a large amount of geothermal energy, however it is small in comparison to their total energy consumption. The Western United States have a large amount of geothermal energy, with a significant hotspot being Yellowstone National Park; much of this energy is currently under-utilised.

Geothermal Power Station, Iceland
Source: ITProPortal

At present, around 20 countries use geothermal energy, with availability largely confined to areas of tectonic activity. Many areas aren't exposed to enough geothermal energy to make use of it on a commercial scale, however, the majority of nations with significant geothermal potential are currently under-utilising this resource. An MIT study (2006), stated that the United States has the potential to produce 100,000 MW of geothermal energy over a 50 year period. Other areas that also have huge potential include East Africa, Indonesia and Japan, with the latter holding the third greatest geothermal potential in the world.

Iceland meets a huge proportion of energy demand with this resource and many other counties have the potential to duplicate this model. Harnessing geothermal energy would allow for faster economic growth of poorer areas such as Indonesia and East Africa and it would allow for significant development using a clean, efficient and relatively cheap resource.

30th November 2014: COP21 Begins

So here we are, the 30th November 2015 and the first day of the COP21 summit in Paris. Since the failure in Copenhagen six years ago, this could truly be a defining moment for both the climate and humanity.

Christiana Figueres opened the summit with the powerful message:

"Never before has a responsibility so great been in the hands of so few. The world is looking to you. The world is counting on you"

151 leaders are in attendance and spoke today about the importance of acting to reduce the impacts of climate change. Here are some of the key messages conveyed by some of the world's leaders on the first day:

- The Prime Minister of Tuvalu stated that the survival of this Pacific island "depends on the decisions we take here in Paris"

- Obama called for a "long-term strategy" rather than a "stop-gap solution" 

- Putin announced that Climate Change is "one of the gravest challenges that humanity is facing" and highlights the increasing economic damage it is causing 

- Angela Merkel stated that "our very future as humankind hinges on this"

- President Xi Jinping of China declared that more must be done by developed nations

- Bolivia's president holds capitalism partially responsible for climate change

- The UK's David Cameron announced that a deal is required for the "poorest and most vulnerable countries in terms of finance" and one that "transfers technology from the richest countries to the poorest countries"

And finally, earlier today ahead of COP21, the inspirational Sir David Attenborough shared a message of hope for renewable energy, particularly solar power. He stated: "the problems are there, but they can be solved". Support from someone so knowledgable and influential surely says a lot. 

Source: BBC News

Morocco's Super-Solar Farm

By 2020, Morocco will provide about half of their electricity from renewable energy and the huge new solar power development in the Sahara desert will help in achieving this. Four developments are planned, with one of these already complete and two others projected to be finished by 2017.

This is a thermal solar farm, using the sun's energy to heat a thermal liquid solution that then generates steam to move turbines. This thermal liquid solution can be used to heat sand which will retain heat for up to three hours, thus enabling electricity generation even after the sun has set.

Not only will this super-solar farm provide clean energy for over a million homes, it also provides a solution to one of solar energy's biggest problems - flexibility.

Ouarzazate Solar Farm, Morocco
Source: heli scsp

See-through Solar

There are many innovative and exciting new ideas and start-ups that are popping up with the intention of improving, invigorating and transforming the renewable energy sector. One start-up that particularly grabbed my attention was Ubiquitous Energy, a company focused on developing see-through solar sheets that have the potential for coating windows, technology screens and many other surfaces exposed to sunlight.

The possible places in which this can be installed are vast and it could revolutionise the way in which devices are charged. Although it efficiency is limited because visible light cannot be captured (as this needs to pass through to make it see-through), light at the UV and infrared ends of the spectrum are absorbed and, in time, there is the possibility of reaching 22% efficiency.

The video below gives more detail about how these see-through solar panels work:

Source: Bloomberg Business 

The Other Side of Solar

My last post was very supportive of solar power and predominately outlined the positives of this technology, however there are can also be negative environmental impacts that can result from poor planning and immature production processes.

Earlier this month, an interesting study by Hu et al. (2015) was published in Nature Climate Change, discussing the regional impacts of solar panels on local climate. The study used models to show regional temperature changes caused by solar farms in both deserts and urban areas. Different scenarios were produced, one of which looked at the effects of a vast global distribution of solar panels. The results showed a local cooling in desert areas with warming in urban areas and an overall net warming of 0.09°C. Due to the outcome of this scenario, the authors made two key points:

1.  The impact of continued fossil fuel consumption would have a far greater detrimental impact on the environment than large scale solar farms

2.  Distribution of solar panels on this scale is highly unlikely therefore a more realistic scenario was modelled with a smaller distribution of solar farms; this resulted in a net cooling of 0.04°C

Desert Solar Farm, Mojave Desert, California
Source: ZME Science

Another study by Dubey et al. (2013) also outlines three potential negative environmental impacts of photovoltaic panels.

1. Toxic chemicals are used in the production of solar cells and accidents can lead to these pollutants entering and impacting local ecosystems

2. At present, fossil fuels predominately power solar panel production therefore the production process is not currently carbon neutral

3. Due to the relatively limited production of solar technology, waste is not currently recycled as it is not yet economically viable

However, all of these issues can be addressed in time; the carbon footprint and lack of recycling can both be improved by greater deployment of this renewable technology and toxic chemical accidents can be reduced through improved regulations.

Renewable technology is usually seen as an answer to all of our environmental problems; however, as we have seen here from solar panels, there are also negative effects. As a result, continued research is imperative so that issues are highlighted, understood and addressed prior to mass deployment. My last post mentioned the rapid 'solar revolution' that is expected to take place, but in light of the studies outlined in this post, I feel that a more balanced approach is required. By ensuring that a wide variety of renewable technologies are rolled out, it will reduce dependency on one resource, meaning that if there are any unforeseen issues once large scale deployment takes place, they can be properly addressed with reduced impact on both energy demand and the environment.

The Solar Revolution?

Of all the renewable technologies, solar has grown the fastest in recent years, with current capacity 48x higher than in 2004. 2014 saw a record 40GW global growth, with the biggest markets being Japan, China and the US. Ontop of this, solar is reducing dramatically in price and this year, it became the cheapest form of electricity in Chile.

Are we about to see a solar revolution?

Many experts claim we are reaching a 'tipping point' where advances in solar technology, such as the Tesla lithium battery that allows solar energy to be stored, will result in rapid and widespread distribution of solar power. A study published earlier this year by Pinner & Rogers (2015), stated that this is the 'age of solar power' and they attribute this to four factors:

1. Regulatory support by governments, including subsidies and feed-in-tariffs

2. Decreasing costs, with prices reducing by up to 8-12% a year

3. Industrialisation; growing demand has led to production process improvements and increased competition which has resulted in cost reductions

4. Improved technology including increased efficiency (currently at about 20%) and developments in storage of solar energy

A UK Solar Farm
Source: The Green Organisation

So, how do photovoltaic panels work?

A photovoltaic panel is made up of a number of cells. These cells are created using two semi-conducting layers (usually silicon). An electric field must be established to enable this to work, which is done by making one layer positive, typically by adding boron, and the other layer negative, by adding phosphorus which adds additional electrons to the silicon.

As a result of this electric field, when a photon from sunlight knocks an electron from an atom, the electron then moves towards the bottom of the cell and is collected on metal conductive plates. From here the electrons are transferred through wires where they flow as an electrical current that can be used as a power source.

Layers of a Photovoltaic Cell
Source: pbs.org

Solar power is hugely flexible, able to power a device as small as a calculator but with the potential to power an entire city. There are continuous advances in this technology and a recent study by Jin et al. (2015), demonstrated progress in increasing efficiency of solar cells by introducing a new oxygen-based coating which enhances the amount of charge carriers, leading to a greater conversion of sunlight into electricity.

With increasing innovation in this area we are seeing rapid advances in solar technology. As well as becoming more efficient, the ability to store solar energy is now an option; as these technologies develop and reduce in price, solar power will become increasingly attractive, gaining more investment and increasing in distribution. I really do hope that the experts are right and we are about to witness this 'tipping point' into widespread installation of solar technology.