Many people wonder what is low carbon energy? You do not need to be an expert to understand the basic concepts that relate to low carbon energy. In this piece we will discuss low carbon energy sources and main concepts related to them. You would be able to distinguish the main differences between low carbon energy sources, how they work, and what the main factors that determine their use are.
Low Carbon Energy sources
The global energy system is in a period of profound transformation. As the world’s population increases, the need for energy is also increasing. By 2030, up to 17% of total global energy demand will be met by renewable energy according to the International Renewable Energy Agency projects. This is a significant development, a trend that is driven both by the need for increased energy security and by the need to reduce greenhouse gas emissions. The writing is on the wall, it is becoming more and more obvious that the need for low carbon energy is important.
Low carbon energy sources provide a cleaner, more efficient, and more reliable alternative to traditional fossil fuel sources. Renewable energy sources in particular, such as solar and wind, produce power without the emissions that come from burning coal, natural gas, and oil.
There are three main fundamental concepts that help guide your understanding around energy systems in general and low carbon energy in particular. Here is the non technical guide to these concepts.
Reliability is one of the most important concepts in energy systems, it means that a system would be able to consistently deliver for extended periods of time with no major interruptions.
To give a real world example, if you happen to own a car, you know that a traditional internal combustion engine (ICE) car will need to be serviced at certain intervals. In addition, the car will need to be fixed due to unexpected events like breaking down on the road. The concept of reliability in this example is as follows: the less the car needs to be fixed or serviced the more reliable it is. This idea applies to energy systems, the longer the system can operate without major disruptions the more reliable it is.
Reliability of energy systems has direct implications on the quality of life for the average person. For example, losing electricity at home is not a good experience, especially if it happens during the coldest or hottest days of the year, due to issues in the electricity grid. Other than the quality of life for the average person, an energy systems’ reliability has far reaching implications in our world, when considered in the context of manufacturing and industrial processes. Continuous 24/7 operations require such high system reliability to be able to deliver lower production costs, and therefore lower cost of goods. This applies to many sectors of the economy including food and critical pharmaceutical products to construction materials and vehicles.
The concept of reliability goes hand in hand with the concepts of uptime and capacity factors. Uptime is the number of hours in a given period (a year for example) the system can operate without disruption, the higher the system’s uptime the better it is. While capacity factor is the amount of capacity they need to have in order to deliver with certainty an amount of energy. (An illustrating example of this is counting how many leaky buckets of water one needs to deliver one bucket worth of water from point A to B)
For low carbon energy systems, the popular renewable energy systems like Solar and Wind have near zero emissions (Scope 1), but these technologies have low reliability, uptime, and capacity factors. This is bad for anyone who wants to use these sources for 24/7, 365 day operation, hence why Solar/Wind + Energy storage offer a more attractive option than solar/wind alone. For example, a Solar photovoltaic plus battery energy storage system provides some guarantees that a system can provide electricity at night when the sun is not shining. Solar thermal plus thermal energy storage can guarantee that the system can provide hot water for heating all day long.
However, low carbon energy sources are not restricted to technologies such as Solar and Wind. In fact, in terms of reliability, uptime, and capacity factors, Geothermal and Nuclear energy are low carbon energy sources that are far superior to Solar and Wind. However, the catch is that they require larger upfront capital investments, lengthy regulatory processes, as well as geographical considerations. The choice of which system to use in what scenario and at what costs is paramount for a low carbon energy system.
In the world of energy systems, cost is king. Lower up-front capital costs are always a top priority. However, fuel costs also play an important role in the total cost of ownership of an energy system, therefore, fuel costs become a critical factor for investment decisions for energy systems. The lower fuel costs the more attractive the energy system becomes. In the context of operations, lower system maintenance costs affect the medium to long term aspects of energy systems.
For example, a geothermal energy plant will have a higher upfront capital cost to build, it also requires specialized talent to build and operate. However, once the plant is in operation, fuel costs are minimal as the energy source is renewable. In the medium and long term (5 to 35 years) the system would need to be maintained and overhauled which will increase the total lifetime cost of the system, however, these costs would be planned and accounted for in the project analysis, therefore there will be some certainty in the energy costs. It is important to highlight that fuel cost certainty is an underrated factor in cost analysis for energy systems. A project that has guaranteed fuel costs over its lifetime will likely mitigate risks that arise from supply-demand market forces and relevant geopolitical events. In this context, renewable energy sources such as solar, wind, and geothermal have this advantage over fossil fuel energy systems and therefore, provide more resiliency in terms of fuel costs.
Zero carbon, low carbon, and carbon neutral energy sources are related, but very different concepts. Wind and solar can produce zero carbon emissions on-site, but this doesn’t mean that they are zero carbon energy systems as a whole over their project lifecycle. This is because there can be carbon emissions produced in production, transport, operation, installation, and decommissioning of such energy sources. This is critical to understanding low carbon energy. If solar panels and wind turbines are produced using materials that are mined using zero carbon energy, transported using zero carbon transport, built using zero emissions construction tools, and maintained using zero emissions methods, then they can be considered zero carbon energy systems. Unfortunately, it is not easy for a system to have all the previous attributes as some limitations will be present on mining, processing, manufacturing, and transport that make it difficult to ensure that such systems do not have embodied carbon in them. Nevertheless, these systems are superior to fossil fuel energy systems and they can be considered low carbon, and would be better than natural gas energy systems. Geothermal energy systems and nuclear power are low carbon systems that can have very low site emissions, but also provide higher system reliability than solar and wind, and better cost certainty compared to traditional fossil fuel energy systems.
Carbon neutrality means that such energy sources come from an origin where carbon has already been removed from the atmosphere, such as sustainable forestry, crops, or from waste processing systems. Carbon neutral energy sources such as biomass, biogas, renewable natural gas, as well as biodiesel are by far the most controversial when it comes to emissions. This is because these energy sources eventually produce carbon emissions on site through an energy system, albeit these systems can produce less carbon emissions than traditional fossil fuels, the use of these systems does not guarantee lower carbon emissions. They are better than traditional fossil fuels, but are not the ultimate low carbon energy systems.
Now that we went over the concepts of reliability, costs, and emissions, you can determine which energy systems are superior and which ones have some drawbacks, which systems have a better chance of competing on costs and which ones do not, and which systems deliver the lowest amount of carbon to the atmosphere and which ones do not. These would be very important guiding principles to anyone who is analyzing low carbon energy systems and making decisions about using these systems to mitigate climate change.