Solar Energy
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Fast Facts
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Before You Watch Our Lecture
Maximize your learning experience by reviewing these carefully curated videos and readings we assign to our students.
Our Lecture
Watch the Stanford course lecture.
Additional Resources
Find out where to explore beyond our site.
Fast Facts About
Solar Energy
Principal Energy Uses: Daylight, Electricity, Heat
Forms of Energy: Thermal, Radiant
Solar energy is radiant energy from the sun—a fully renewable energy resource. We use the solar resource to provide daylight, electricity, and heat in four ways (in order of prevalence):
- Indirect: Our primary use of the sun’s energy is for free light and warmth (not counted in the data below but important for energy efficiency)
- Solar PV: Converting photons (light) into electricity through photovoltaics (PV), also known as solar panels
- Direct (solar thermal heat): Using the sun to heat water and buildings (hot water, warm pools, space heating/cooling)
- Solar Thermal Power (CSP): Concentrating sunlight to produce high-temperature heat to generate electricity, sometimes called concentrating solar power (CSP)
Solar PV is the fastest-growing electricity resource in the world. It is fully renewable with few environmental impacts, and the cheapest source of electricity in many countries.
Significance
Energy Mix
2% of world 🌎
(#7 resource)
1% of US 🇺🇸
(#8 resource)
Electricity Generation
5% of world 🌎
(#6 resource)
3% of US 🇺🇸
(#6 resource)
Global Solar Use
Solar PV 74%
Solar thermal heat 25%
CSP 1%
Global Solar PV
Most Installed Capacity
China 37% 🇨🇳
of global installed capacity
Most Generation
China 33% 🇨🇳
of global solar electricity
Highest Penetration
Chile 16% 🇨🇱
of country’s electricity comes from solar
Change in Global Solar PV Electricity Generation
Increase:
⬆ 197%
(2017-2022)
US Solar PV
Most Installed Capacity
California 27%
of US installed capacity
Most Generation
California 29%
of US solar electricity
Highest Penetration
California 27%
of state's electricity comes from solar
Global Solar Thermal Heat
Most Installed Capacity
China 73% 🇨🇳
of global installed capacity
(US has 2.5%)
China’s main use is for heating buildings and water, while the main use in the US is for heating swimming pools
Change in Global Solar Thermal Heat Capacity
Increase:
⬆ 15%
(2017-2022)
Global Solar Thermal Power (CSP)
Most Installed Capacity
Spain 37% 🇪🇸
of global installed capacity
(US has 21%, 64% of which is in California)
Change in Global CSP Capacity
Increase:
⬆ 29%
(2017-2022)
Costs of US Solar PV
Costs increase as size of installation falls:
- Utility scale: largest scale, unsubsidized LCOE* = $24 - $96
- Community, commercial, industrial: medium scale, unsubsidized LCOE = $49 - $185
- Rooftop solar / residential: smallest scale, unsubsidized LCOE = $177 - $282
*LCOE (levelized cost of energy) - allows for the comparison of different electricity generating technologies
Compare costs with subsidies and for other resources on the Introduction to Renewable Energy Fast Facts
Costs of solar PV have fallen over time:
Drivers
- Abundant, nondepletable source of energy
- Low climate and environmental impact
- Utility-scale solar PV: very low LCOE relative to fossil fuels, competitive with onshore wind
- Continued PV cost declines and productivity gains
- Declining energy storage costs enable grid integration
- No fuel price volatility/risk
- Short implementation timeframe from project start to electricity generation
- Financial incentives (investment tax credit)
- Renewable energy/climate targets
- Rooftop solar PV: no transmission needed; no additional land use
- Solar thermal heat: low-cost option for heating buildings, certain industrial processes
Barriers
- Grid integration challenges due to intermittency and duck curve*
- Inconsistent/decreasing incentives
- NIMBY/BANANA** concerns
- US economic sanctions against panels manufactured in China, which is the largest solar PV manufacturer in the world
- Lack of solar PV recycling capacity at end of life
- Rooftop solar PV: very high LCOE; net metering reforms and utility rate redesign threaten economic viability
- Solar thermal heat: hard to reach high enough temperatures for certain industrial processes
*Non-solar power plants are forced to ramp up quickly when the sun goes down because solar electricity drops and net demand peaks
**NIMBY - not in my backyard; BANANA - build absolutely nothing anywhere near anything
Climate Impact: Low
- Near-zero emissions
Environmental Impact: Low
- No air pollution
- Little / no water use
- Land use and habitat impact can be significant
Before You Watch Our Lecture on
Solar Energy
We assign videos and readings to our Stanford students as pre-work for each lecture to help contextualize the lecture content. We strongly encourage you to review the Essential videos and readings below before watching our lecture on Solar Energy. Include selections from the Optional and Useful list based on your interests and available time.
Essential
- Intro to the 4 Ways We Harness the Solar Resource + Deep Dive on Solar Thermal Heat. Stanford Understand Energy. October 2022. (13 min)
An overview of the primary ways we harness the solar resource and provides a more in-depth look at the direct use of solar thermal heat. - Solar Thermal Electricity / Concentrating Solar Power. Stanford Understand Energy. May 13, 2021. (25 min)
A more in-depth look at solar thermal electricity, also known as concentrating solar power. - How Do Solar Panels Work?. Richard Komp. TEDEd. January 5, 2016. (5 min)
Examines how solar panels convert solar energy to electrical energy. - California Now Requires Solar Panels on All New Homes. That’s Not Necessarily a Good Thing. Vox. January 2, 2020. (5 pages)
Reviews the pros and cons of California's requirement that new houses must be built with solar panels.
Optional and Useful
- Solar Farm Virtual Tour. MidAmerican Energy. August 15, 2013. (6 min)
A brief history of solar energy and an overview of constructing and operating a solar farm. - Solar 2021. NEED.org. 2023. (4 pages)
An excellent overview of the solar resource.
Our Lecture on
Solar Energy
This is our Stanford University Understand Energy course lecture on solar energy. We strongly encourage you to watch the full lecture to understand solar as an energy system and to be able to put this complex topic into context. For a complete learning experience, we also encourage you to watch / read the Essential videos and readings we assign to our students before watching the lecture.
Presented by: Kirsten Stasio, Adjunct Lecturer, Civil and Environmental Engineering, Stanford University; CEO, Nevada Clean Energy Fund (NCEF)
Recorded on: May 17, 2024 Duration: 53 minutes
Additional Resources About
Solar Energy
Stanford University
- Stanford Solar Car Project
- Bent Research Group
- Materials Science & Engineering Department
- Mark Brongersma - Photovoltaics
- Yi Cui - Batteries and fuel cells, electric grid, grid scale storage, photovoltaics
- Reinhold Dauskardt - Batteries and fuel cells, photovoltaics, solar thermal
- TomKat Center for Sustainability
- Stacy Bent - Photovoltaics, batteries and fuel cells
- Gabelle Laboratory for Advanced Materials (GLAM)
- StorageX Initiative
Fast Facts Sources
- Energy Mix (World 2022): Energy Institute. Statistical Review of World Energy. 2023.
- Energy Mix (US 2022): US Energy Information Agency (EIA). Total Energy: Energy Overview, Table 1.3.
- Electricity Mix (World 2022): Energy Institute. Statistical Review of World Energy. 2023.
- Electricity Mix (US 2022): US Energy Information Agency (EIA). Total Energy: Electricity, Table 7.2a.
- Global Solar Use (2022): International Energy Agency Solar Heating & Cooling Programme (IEA SHC). Solar Heat World Wide. 2023.
- Global Solar PV Most Installed Capacity (2022): Energy Institute. Statistical Review of World Energy. 2023.
- Global Solar PV Most Generation (2022): Energy Institute. Statistical Review of World Energy. 2023.
- Global Solar PV Highest Penetration (2022): Energy Institute. Statistical Review of World Energy. 2023.
- Global Solar PV Electricity Generation Change (2017-2022): Energy Institute. Statistical Review of World Energy. 2023.
- US Solar PV Most Installed Capacity (2023): Solar Energy Industries Association (SEIA). Solar State-By-State Map.
- US Solar PV Most Generation (2022): US Energy Information Agency (EIA). Electricity Data Browser.
- US Solar PV Highest Penetration (2022): National Renewable Energy Lab (NREL). Spring 2023 Solar Industry Update. 2023.
- Global Solar Thermal Heat Most Installed Capacity (2022): REN21. Renewables 2023 Global Status Report: Renewables in Energy Supply. 2023.
- Global Solar Thermal Heat Capacity Change (2017-2022): REN21. Renewables 2023 Global Status Report: Renewables in Energy Supply. 2023.
- CSP Most Installed Capacity (2022): REN21. Renewables 2023 Global Status Report: Renewables in Energy Supply. 2023.
- CSP Global Capacity Change (2017-2022): REN21. Renewables 2023 Global Status Report: Renewables in Energy Supply. 2023; REN21. Renewables 2018 Global Status Report: Renewables in Energy Supply. 2018.
- Costs of US Solar PV Installations by Size: Lazard. LCOE. April 2023.
- Costs of US Solar PV Over Time: Lazard. LCOE. April 2023.
More details available on request.
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