Below, we compare different solar energy systems.
Those systems are Solar PV (photovoltaic), and also Solar Thermal (CSP – Concentrating Solar Power) Energy.
We look at what each one is, their main differences, and provide examples of each.
Summary – Solar PV vs Solar Thermal/CSP
Different Solar Energy Systems
Solar PV and Solar CSP are different solar technologies
Uses
Solar PV might mainly be used for electricity
Solar CSP might mainly be used for electricity, or heating water
Scale Of Use Of Solar PV
Solar PV is commonly used on different scales, such as:
– On a large utility scale
Big solar farms with hundreds or thousands of panels that produce electricity for utilities
– Or, on a distributed residential scale
For individual households, buildings and locations
Which Is More Popular/More Prominent?
Solar PV (photovoltaic) currently leads Solar Thermal/CSP by a very wide margin across different metrics
Those metrics include annual investment of money, annual and total installed capacity, electricity generation, and electricity consumption
Potential Trends For The Future
This trend of PV outpacing CSP might continue into the future with continued investment in, and expansion of Solar PV projects.
Although, solar CSP might still be expected to grow into the future
Potential Benefits & Drawbacks Of Each
Solar PV is more popular
However, solar CSP might have a few small advantages over Solar PV, such as dispatchability, and also generating electricity while the sun is down
What Is Solar PV?
Description
Solar PV means ‘Solar Photovoltaic’
A photovoltaic system converts energy from sunlight into electricity
They usually involve the use of photovoltaic cells, which capture the sunlight
A solar panel is a common example of a solar PV system
What Solar PV Is Used For
Solar PV is mainly used for energy generation and electricity generation
Scale Of Solar PV Use
Solar PV can be:
– Utility scale
Such as solar farms
– Or, distributed
Usually rooftop installations and other standalone solar cells that help stabilise or support a power system in the event of power disruptions, blackouts etc.
How Solar PV Works
The general process, in order, and paraphrased from vivintsolar.com, might include:
1. Sunlight (which is composed of light photons) hits solar cells
2. The solar cells convert sunlight into DC electricity
3. The DC electricity is fed into an inverter that turns DC energy into AC electricity for use
4. Some electricity may either be stored in an energy storage battery, or, fed back into the grid
What Is Solar Thermal/CSP?
Description
Solar CSP means ‘Solar Concentrated/Concentrating Solar Power’
CSP systems use the Sun’s thermal energy to generate electricity or heat water
Types Of CSP Plants
Some of the different types of Solar Thermal plants might include:
– Linear Fresnel
– Tower
– Dish and Trough
How Solar Thermal/CSP Works
A paraphrased summary from wikipedia.org, sciencedirect.com, cleanenergycouncil.org.au and irena.org:
Solar CSP uses mirrors (lenses and reflectors) to capture the Sun’s thermal energy (infrared radiation) to heat a (thermodynamic) liquid or an oil, create steam, drive a heat engine/generator, and generate electricity
What Solar CSP Is Used For
Solar CSP is used for heating, and also energy generation (and electricity generation)
Solar CSP can also be used for desalinating water
Statistics For Solar PV vs Solar CSP Capacity, Production & Consumption
Annual Additional Installed Capacity
Between 2012 to 2018, solar PV led all renewables in annual additional installed capacity by a wide margin (55% alone in 2018), followed by wind energy, hydropower, and all other renewables as a group behind that (including solar CSP/thermal) (vox.com)
Global Electricity Production
Solar thermal/CSP made up 0.4% of total global electricity production in 2018 along with other renewables like geothermal and ocean power (vox.com)
Solar PV vs Solar CSP Installed Capacity
In 2018, global Solar PV installed capacity was 480,357 MW, and Solar CSP was 5,469 MW (irena.org)
Solar PV vs Solar CSP Electricity Generation
In 2016, Solar PV electricity generation was 317,613 GWh, and Solar CSP was 11,037 GWh (irena.org)
% Of Worldwide Renewable Energy Consumption
In 2017, solar PV and solar thermal were both responsible for 4% each of renewable energy consumption worldwide (iea.org)
Solar PV vs Solar Thermal – Differences, & Similarities
Similarities
Solar PV and Solar Thermal are both used on the large utility scale, and on the smaller distributed/individual scale.
Variables
Cost, efficiency, and other variables can differ between the two depending on the scale they are used at.
Differences
Apart from the obvious differences of amount of investment investment, installed capacity, electricity generation and electricity consumption, and how they actually work (light energy vs heat energy), some of the key differences at the utility/large scale are:
– Dispatchability
[Solar CSP] provides a dispatchable energy supply – that is, their power output can be adjusted based on grid demand.
This makes them more flexible than traditional solar PV plants.
– cleanenergycouncil.org.au
– Generating Energy/Electricity When The Sun Isn’t Out
One of the main advantages of a CSP power plant over a solar PV power plant is that it can be equipped with molten salts in which heat can be stored, allowing electricity to be generated after the sun has set (irena.org)
– Using At Large Scales
Overall, CSP on the utility scale probably faces more barriers and challenges than Solar PV which is far more widely used
– Use For Electricity Generation vs Heating
Solar thermal has more of a use for heating water on homes, whereas solar PV panels might be used more frequently for electricity.
– Other Differences
On a household and individual level, greenmatch.co.uk mentions some of the cost, efficiency, flexibility and other differences between the two technologies at greenmatch.co.uk
Future Of Solar PV & Solar CSP
According to various reports, both solar PV and solar thermal might be expected to grow in the future.
Forecasted Growth Stats For Solar PV
By 2023, solar PV is expected to grow to 8% of renewable energy consumption worldwide …(iea.org)
From iea.org:
[There is expected to be] a 46% growth over the period 2018 to 2023 in renewable energy as a whole … with solar PV accounting for more than half of this expansion [and, supportive government policies and market improvements are some of the main causes]
Utility-scale projects represent 55% of this growth
China alone accounts for almost 45% of global solar PV expansion
Forecasted Growth Stats For Solar CSP
By 2023, … solar thermal is expected to stay the same at 4% [of renewable energy consumption worldwide] (iea.org)
CSP is expected to grow 87% (4.3 GW) over the forecast period [of 2018 to 2023], 32% more than in 2012‑17 (iea.org)
Potential Barriers Facing Solar CSP In The Future
[Some of the barriers facing CSP expansion individually are] technology risk, restricted access to financing, long project lead-times, and market designs that do not value storage continue to challenge CSP deployment (iea.org)
Examples Of Solar PV & Solar Thermal Worldwide – Largest Solar Farms, & Countries With The Most Solar PV & Solar CSP
Largest Solar Power Stations
You can view lists of the largest solar PV and solar thermal power stations in the wikipedia.org resources listed in the sources list at the bottom of this guide
Countries With The Largest Installed Capacity For Solar PV
In 2018, China, Europe, the US, Japan and Germany had the highest installed capacities of Solar PV in MW (wikipedia.org)
Countries With The Largest Installed Capacity For Solar CSP
In 2016, Spain and the US easily had the highest installed capacities of Solar CSP in MW (wikipedia.org)
Global Installed Capacity, Production & Consumption Of Solar Energy
Worldwide, solar energy installed capacity, production and consumption stats are:
At the end of 2018, solar as a whole made up 20% of installed capacity for renewables
At the end of 2018, solar PV made up 2.4% of total global electricity production
At the end of 2016, solar was the third most consumed renewable energy source for electricity
Investment In Solar Energy
Sources
1. https://www.bettermeetsreality.com/installed-capacity-production-consumption-of-renewable-energy-worldwide-by-country-by-source/
2. https://www.bettermeetsreality.com/countries-that-invest-the-most-in-renewable-energy-what-they-invest-in/
3. https://www.bettermeetsreality.com/the-different-types-of-renewable-energy-sources-with-examples/
4. https://en.wikipedia.org/wiki/Solar_power_by_country
5. https://www.sciencedirect.com/topics/engineering/solar-thermal
6. https://www.vox.com/energy-and-environment/2019/6/18/18681591/renewable-energy-china-solar-pv-jobs
7. https://www.iea.org/renewables2018/
8. https://www.iea.org/renewables2018/power/
9. https://www.irena.org/solar
10. https://www.vivintsolar.com/learning-center/how-does-solar-power-work
11. https://www.cleanenergycouncil.org.au/resources/technologies/solar-thermal
12. https://en.wikipedia.org/wiki/List_of_photovoltaic_power_stations
13. https://en.wikipedia.org/wiki/List_of_solar_thermal_power_stations
14. https://www.greenmatch.co.uk/blog/2015/04/solar-panels-vs-solar-thermal
15. https://www.iea.org/newsroom/news/2018/october/modern-bioenergy-leads-the-growth-of-all-renewables-to-2023-according-to-latest-.html
I don’t buy the argument that only CSP can store thermal energy. The truth is that regardless whether a CSP or PV system is used to capture the solar energy, in both cases energy could be stored as thermal energy (molten salts or whatever material is chosen). I note it would be foolish to do this from PV if the intended end use is electricity however if the intended end use is thermal (eg defray gas-fired DHW, space heat, process heat) then thermal storage may be cheaper than battery storage for PV.