Net Zero

What is renewable energy?

Renewable energy is a term that all of us will be well aware of by now. It has managed to find a spot in our vocabulary with many of us still having no idea what it actually is. Many could ramble through an explanation, maybe hitting a few buzzwords along the way – but there is no genuine understanding there. If you were to ask a hundred people to explain the difference between renewable and non-renewable energy, you would likely receive a hundred entirely different answers.

So, what is the difference between renewable energy and… energy? Both traditional fuel sources and renewable energy finish at the same finish-line, they just run very different races.

The main difference is the original source of the energy. Traditionally there has been a reliance on finite fossil-fuel sources – burning things like coal to release and utilise the energy stored within. The problem with these fuel-types is that they are both incredibly dirty, and will run out eventually. There is a limited amount of coal held within the earth, and it is not replaced after extraction.

Renewable energy comes from clean, naturally replenishing sources. It does not matter how much energy we harvest from the tide, as it will keep rising and falling the following day for us to harvest all over again. Renewable energy implies that we will be able to continue exploiting the source indefinitely. There are some small exceptions to this, as we will soon discover.

The seven sources of renewable energy

There are seven main sources of renewable energy that are exploited globally. All are at varying stages of development with pros and cons for each. Some have been commonplace for years, while others are facing massive barriers.

The seven sources of renewable energy are as follows:

• Solar
• Wind
• Tidal
• Geothermal
• Biomass
• Hydro-electric
• Solar (heat)

It may be slightly confusing to see solar energy on the list twice – but this is due to two completely unique methods of electricity production. The solar energy we are all most comfortable with and see daily in the form of solar panels relies on a process called the ‘photovoltaic effect’.

The other type of solar energy sourced from the sun relies on the heat from the sun, rather than photons from sunlight. This type of solar energy is far newer, and is nowhere near as commonplace. By installing huge fields of solar panels in direct beating sunlight, it allows production sites to focus the heat from the sun onto a heat-carrying medium with the aim of turning it into steam, to drive turbines and generate electricity. This type of production site is referred to as a CSP plant (concentrating solar panel). Source: You Matter

5 characteristics of successful renewable energy

• Clean, non-polluting
• Low greenhouse gas emissions and toxic waste
• Reliable in the long-term
• Cost-effective
• Efficient

The dirty truth behind clean solar energy

With renewable energy sources – we are often led to believe that there is no downside. That we do not need to feel guilty from this type of exploitation. But should we maybe be feeling just a little bit of guilt?

The truth is that solar energy is not completely morally perfect – and have negative environmental consequences too. Photovoltaic panels are made with minerals like silicon (often in the form of quartz), copper, nickel, and cadmium. These minerals are not quite as easily accessible as the other factors of production needed for solar energy production – and will require a bit of digging to extract them.

I’ll rephrase that last sentence – they will require a lotof digging to extract them.

All of these minerals are trapped deep within the earth and the energy needed to extract them is astronomical. It takes fifteen seconds to type in a quick google image search for these mines, it does not take an environmental genius to figure out that the mines needed for solar panel production are not sustainable.

Massive excavators tearing into the earth, vehicles guzzling petrol, machines billowing smoke, horrible working conditions – and for the most part, this is all happening in underdeveloped nations where cheap labour can be exploited. Huge volumes of water are used throughout the entire process, the terrain is left utterly destroyed, habitats of endangered species are completely wiped, silicosis is rampant in workers from exposure to silica dust. As can be seen all to often from developed nations – they do not solve problems, simply outsource them to underdeveloped nations.

There is also scope for further problems along the production process – even after extracting raw materials. Once silicon has been extracted, it needs to be turned into high quality silicon. The process for creating this polysilicon produces incredibly harmful fumes (silicon tetrachloride) and contributes to soil acidification.

Following the creation and shaping of polysilicon, chemicals are used to maximise light intake. Chemicals such as hydrofluoric acid are used, but if this isn’t disposed of correctly there is scope for huge environmental damage. Even the name ‘hydrofluoric acid’ sounds toxic.

 Should I tear the solar panels off my roof?

No, not just yet.

It is true that there are damaging aspects from the production process of solar panels. But the fact remains that these pale in comparison to the negative aspects of the fossil fuel industry. The production of solar panels does need further improvements that is true, but on the whole they are still incredible pieces of technology.

There are processes that have recently been developed that takes the toxic silicon tetrachloride and converts it back into polysilicon, increasing yield and lowering negative side effects. Further to this, researchers at the National Renewable Energy Laboratory in the United States have begun to investigate how to develop polysilicon without creating any silicon tetrachloride as a by-product.

There are also manufacturers who have listened to the calls for concern surrounding their toxic chemical use. There is a slow switch towards using safer alternatives like sodium hydroxide and zinc sulfide, and further research into other potential replacements.

This is one key area in which the renewable sector will always differ from fossil fuel extraction. Although solar panels are not quite at the stage where they are 100% ethical and renewable – they are certainly heading in that direction. There is such a wide focus on developing good practice further and improving every single stage of production.

Just because solar panels aren’t completely ethical, does not mean they are not the most ethical.

“The EU ETS is the largest multi-country, multi-sector greenhouse gas emissions trading system in the world.” – Gov.uk

Included within this system is over 11,000 power-stations and industrial plants across the EU – with 1,000 or so of these within the UK itself. These are not limited to one specific industry – the list includes power-stations, offshore oil platforms, iron and steel producers, oil refineries, and chemical producers. All of these industries are known for having incredibly high energy-demands.

Other companies may also be included in this list that don’t belong to these industries. Organisations and companies are usually included based upon the combustion capacity of equipment at their business site.

How does the EU ETS work?

EU ETS works on the fundamental basis of ‘cap and trade’. There is a limit placed on the total greenhouse gas emissions allowed for participants within the EU ETS. This cap is then converted into tradeable permits (credits) that can be thought of as ‘tradeable allowances’.

These credits are allocated to members in the market through a mix of allocation and auctions. Those entities who give off higher emissions than others will now have more of a financial burden to purchase more credits, to cover off their higher emission numbers. Those who’s emissions are below their allocation are free to sell on their credits – receiving monetary compensation for being emission-friendly. This system effectively punishes those who’s emissions are too high, and rewards those who come in under the limit.

All companies covered by EU ETS are required to report and monitor their emissions every year – surrendering any emission allowances to cover annual emissions. This data helps the cap level to be calculated as accurately as possible.

Over-time, the cap is gradually reduced. Taking into account new research, technology, good practice, and previous emissions data to set a smaller limit year after year. This falling cap should lead to a fall in total emissions year upon year.

Has the EU ETS been a success?

This is up for debate still. Some traditional economists argue against the efficacy of the system.

However, data from ec.europa.eu shows that between 2005 and 2019 that emissions have fallen by 35% across all installations covered by the system.

More recently, the Market Stability Reserve was introduced in 2019. This has helped contribute to a higher and more stable carbon price (some of the things that traditional economists disliked). Since this was introduced – emissions have fallen by 9% in 2019, with reductions of 14.9% and 1.9% from electricity and heat production, and industry emissions respectively. The amount of carbon credits supplied each year are planned to be reduced annually, also.

Where does the EU ETS go from here?

The European Green Deal was presented in September 2020 – which included an impact-assessed plan to further improve on the emission reductions already made. By 2030, greenhouse gas emissions will be moved to at least a target of 55% in reduction. Further proposals will be made in June of this year regarding the legal side of things – so keep an eye out for any further developments.

How does this effect the energy industry?

Energy producers across Europe are some of the biggest customers for carbon credits. As they release huge-emissions in trying to produce energy for the millions of homes and businesses that need it, they need to purchase the necessary amount of carbon credits.

As we have already covered in the previous sections – total carbon credit allowances are planned to fall year after year. This, combined with rising energy demand across Europe, will create an incredibly tight squeeze on energy producers.

As the market cap is designed to be reduced year after year, this is a slow but observable reduction in the total supp

Differences in desires – how will this affect the system?

Action	Comment
President Macron has called for a serious rise in costs.	France has further implemented a fixed carbon tax of €44/mt for petroleum products, set to rise to €84/mt in 2022.
Germany is still hugely reliant on coal.	Germany is still dependant on coal as an energy source, which a higher ETS would punish disproportionately.
The UK has left the EU.	The UK has left the EU and since started their own carbon trading system.
The Paris Agreement may triple prices.	A study from carbon tracker estimates that prices could triple if they are to use the EU ETS to hit Paris Agreement targets.
European coal production looks bleak.	New prices for carbon look set to end coal production across Europe.
Diversity within the EU.	There are different member states all pushing and pulling for different things.

The biggest thing to understand is that the EU ETS is subject to more external pressure than is immediately evident. Here are a few things to think about, which have pros and cons attached to all of them.

As you can see – each member state of the EU will push and/or pull in the direction that best suits their countries interest. France, an incredibly wealthy nation, have self-imposed further carbon taxes. Compare this to Germany who still source a huge amount of their energy from coal (high emissions) and who look set to take a huge hit from higher ETS prices.

The EU ETS is certainly not isolated from the political sphere either – with the withdrawal of the UK from the EU, it shows how exposed the scheme can be left. How will the trading system cope with the sudden removal of 1,000 customers?

This table is by no means inclusive of all commentary surrounding EU ETS – but it is a start. It is important to be able to critically think about the mechanisms we take for granted around us. By being able to understand how and why some of the factors influence the EU ETS in the way that they do

What is ‘renewable’ energy?

Renewable energy is a term that all of us will be well aware of by now. It has managed to find a spot in our vocabulary with many of us still having no idea what it actually is. Many could ramble through an explanation, maybe hitting a few buzzwords along the way – but there is no genuine understanding there.

We aim to change that.

What is the difference between renewable energy and… well, energy? Both traditional fuel sources and renewable energy finish at the same finish-line, they just run very different races.

The main difference is the original source of the energy. Traditionally there has been a reliance on finite fossil-fuel sources – burning things like coal to release and utilise the energy stored within. The problem with these fuel-types is that they are both incredibly dirty, and will run out eventually.  

Renewable energy comes from clean, naturally replenishing sources. It does not matter how much energy we harvest from the sun, as it will keep shining the following day for us to harvest all over again. Renewable energy implies that we will be able to continue exploiting the source indefinitely.

Solar Energy

Sunlight is fortunately one of the most abundant sources of renewable energy – and can be found and harnessed all across the globe. It is incredible to think that the total amount of energy that hits the surface of the earth in one hour is more than enough to satisfy our yearly energy demands.

Solar energy is certainly beginning to be a lot more commonplace too – just take a short drive to the local shops and no doubt you will be able to spot a few solar panels installed on some roofs.

Solar energy uses slices of crystalline silicon to produce solar cells that are then placed in direct sunlight. These panels then absorb photons from sunlight and convert them into electrons. This is a process called ‘the photovoltaic effect’. Source: Phys

In the past, solar-panels were only ever used by small or medium-sized installations to generate just a little energy. However, in the last thirty or so years, this has changed dramatically.

The biggest issue facing solar energy production – is how to deal with no sun. This is just common-sense, but the amount of solar energy that can be used is directly dependant on time of day, season, location, and weather. It is easy to

Wind Energy

It is worth noting that humans have been harnessing the power of the wind for thousands of years. Traditional wind-mills to drive grind-stones, large sail-boats to traverse oceans, or even using it to drive rudimentary water-pump systems.

Thousands of years of use across a whole host of different sources, and we are still no closer to running out as the day we started – how incredible.

These days, wind energy is harnessed through massive turbines planted upright into the earth. The huge blades of the turbine will begin to spin when hit by wind, which will then run a generator that will turn the kinetic (moving) energy into electrical energy that can then be used in homes across the country. It is a common misconception that winds will have to be fast-moving or strong in order to begin turning turbine blades.

It is true that the faster the wind blows, the more electricity will be generated. This only holds true to a certain level, however. When wind-speed doubles almost eight times as much electrical energy is produced. If the wind passes into the threshold of being too strong then turbines will shut down to protect against any unnecessary damage.

Not every site is suitable for installation of wind-turbines. It is difficult to find the right conditions that are needed to run wind-farms/turbines at their production capabilities. There are few countries in the world that are blessed with the consistent wind and suitable landscape needed to build large-scale wind farms.

Luckily for us in the UK, we are perfectly situated on the North-West tip of Europe to be exposed to just the right amount of wind. Scotland in particular is actually the windiest country in the whole of Europe, which has led it to be dubbed as the…

“…Saudi Arabia of wind power…”

– Boris Johnson, Prime Minister of the UK

Tidal Energy

Tidal energy is still in its infancy when compared to other sources of renewable energy.

Our oceans cover around 70% of the earth’s surface. If we were able to unlock the secrets to harnessing the energy that is currently left untapped there, then it is difficult to see us ever struggling for renewable energy ever again. Tides are steady and predictable – which sounds great, in theory.

The problem with tidal energy lies in the logistics. It is incredibly difficult to find a suitable location that contains enough wave power, as-well as fulfilling other financial and logistical check-boxes. Historically, cost has always won the trade-off with reward. In other words, investors think tidal energy projects are too expensive and the potential returns/reward simply does not justify original investment.

Recent technological developments and improvements in turbine design and technology have actually improved this. By increasing potential returns and lowering costs, tidal power projects are finally starting to receive the attention (and more importantly, funding) that they deserve.

In 2015 – the first ever grid-connected wave-power station went online off the coast of Western Australia. This project, dubbed CETO after the Greek goddess of the sea, was developed by Carnegie Wave Energy. The power station cleverly operates underneath the surface of the water by using undersea buoys to pump a series of pumps anchored onto the sea-floor, which in turn will generate electricity. It is still early days – but tidal energy is coming, a lot faster than many anticipated. Source: Phys

Geothermal Energy

Geothermal electricity relies on the heat that is naturally produced by and from the earth. This can be from sources like magma conduits, hot-springs, or even hydrothermal circulation. This heat is then either harnessed to produce steam and spin turbines and generate electricity, or directly used to heat buildings.

A huge problem with taking geothermal energy production further is that there is a severe lack of suitable sites to be found. How often do you encounter a natural hot-spring in your day-to-day life? Or, if there are multiple sites then they often lie in close proximity to another or in an area too remote or hostile to develop infrastructure. This means that only very few countries can even possibly produce geothermal electricity.

What it does offer, is an opportunity for countries with high-levels of geothermal activity to exploit an easily accessible and cheap fuel-source. This encourages the migration away from fossil-fuel energy sources wherever possible. When talking about ‘world-leaders’ in renewable electricity production, it is often the same handful of wealthy countries that will crop up. Geothermal electricity allows countries like El Salvador, Costa Rica, The Philippines, Kenya, and Iceland to enter the conversation. This is not just a random list, but rather a list of countries who currently source more than 15 percent of their energy demands from renewable geothermal sources.

Biomass Energy

Biomass can be considered to be any organic material from plants or animals – which can include crops, waste wood, or even animal by-products. Most commonly the biomass will be burned and energy released as heat, which can be harnessed to drive a steam turbine and generate electricity.

It may be surprising to some that burning biomass is considered to be renewable. Is it really sustainable to burn thousands of acres of forest in order to generate electricity? Biomass energy production is often labelled as clean, renewable, and a brilliant alternative to fossil fuels.

This isn’t universally true however, as many forms of biomass will actually produce higher carbon emissions than some fossil fuels. Not only this, but some sources are incredibly damaging to local flora and fauna.

When looking for great renewable sources of biomass – it is better to focus on any waste produce from industry. It is now common practice for large sawmills to gather sawdust and wood-chips and send them onwards to be burnt. Although there are still emissions released, these are mitigated somewhat by the fact that the chips would simply be left to rot otherwise.

Hydro-Electric Energy

Hydro electric electricity generation relies on fast-moving water as a source of renewable energy generation. Fast moving water is sourced in either large rivers, or rapidly-descending water from hills and mountains. This energy is used to spin turbine blades that will be transformed into electrical energy by a generator. It is almost comparable to a re-imagined wind energy turbine.

The jury is still out regarding the classification as a renewable energy source, but this is more a case of semantics rather than any ground-breaking scientific discovery. There have been well-documented cases of huge hydro-electric dams diverting and restricting natural flows of water – negatively impacting reliant human and animal populations. In any cases of dam failure, the results are catastrophic. The Mekong basin flood in Southern Laos as a result of a nearby hydro-electric dam failure, and should be used as a case-study of poor practice. Read about it here

The nature of this and other failures in hydro-electric power plants are mainly down to scale of operation, which is why it is deemed to be semantics. Huge dams are far more likely to permanently alter natural flows of rivers or rapids, which leads to them being deemed as ‘non-renewable’. Small hydro-electric plants that are carefully managed have been shown to not have the same adverse effects (any site with production less than 40 megawatts). Source: NRDC

Solar Energy – Heat

In order to avoid confusion, this renewable source has been left until last to deal with. We have already covered how solar energy can be transformed by the photovoltaic effect into usable electricity, much like how a plant would harness the sun’s energy. There is another method in which we can harness the sun’s power.

CSP plants (concentrating solar panels) concentrate the heat from sunlight, and use this thermal energy instead of the photovoltaic effect. This is done through complicated series of high-powered lenses and mirrors focussing sunlight onto a heat-carrying medium and turning it into steam to drive turbines. This technology is not quite as developed as other areas of solar renewable energy. Source: National Geographic

As you can imagine, CSP faces much of the same problems as other areas of renewable energy production. There is an incredible shortage of CSP experts, as so many solar energy specialists are headhunted into photovoltaics. Issues with funding arise commonly, as capital start-up costs and manpower costs are astronomical. Not only this, but there are very few suitable locations for CSP plants due to the need for intense year-round sunlight.