Solar power is the conversion of energy from sunlight into electricity, achieved through two primary methods: photovoltaics (PV) and concentrated solar power. Photovoltaic cells utilize the photovoltaic effect to directly convert light into electrical current, while concentrated solar power systems employ lenses, mirrors, and solar tracking mechanisms to focus sunlight on a specific point, often to generate steam for driving a turbine.
Initially, photovoltaics were primarily used for small and medium-scale applications, from calculators powered by a single solar cell to remote homes equipped with off-grid rooftop PV systems. Commercial concentrated solar power plants began to emerge in the 1980s. Over time, the cost of solar electricity has significantly decreased, leading to exponential growth in the capacity and production of grid-connected solar PV systems, roughly doubling every three years. In 2021, approximately half of new electricity generation capacity was solar-based.
In 2022, solar power contributed 4.5% of the world's electricity, a substantial increase from the 1% recorded in 2015 when the Paris Agreement to combat climate change was signed. In most countries, utility-scale solar, along with onshore wind, boasts the lowest levelized cost of electricity for new installations.
Notably, nearly half of the solar power installed in 2022 came from rooftop installations. Incorporating low-carbon power sources like solar is essential for addressing climate change. Nevertheless, challenges remain, including grid integration and addressing policy, regulation, and financing obstacles, as highlighted by the International Energy Agency in 2022.
The potential for solar energy generation is influenced by geography, with areas closer to the equator receiving higher solar radiation. Photovoltaic systems that track the Sun's position can increase energy potential in regions farther from the equator. Time variations, such as nightfall and cloud cover, affect the daily energy absorption by solar panels.
Additionally, land availability plays a crucial role in determining solar energy potential. Solar panels require unused and suitable land or rooftop space for installation. Solar cells can be integrated into roofs, making use of residential and commercial buildings. Alternatively, solar plants can be established on unused lands, provided they meet the necessary criteria.
Two primary technologies are used in solar power plants:
Photovoltaic (PV) Systems: These systems use solar panels, which can be installed on rooftops or in ground-mounted solar farms. Solar panels directly convert sunlight into electrical power.
Concentrated Solar Power (CSP): CSP systems utilize mirrors or lenses to concentrate sunlight, generating extreme heat to produce steam. This steam is then used to drive a turbine and generate electricity.
Solar cells, also known as photovoltaic cells, are the fundamental components of PV systems. They convert light into electric current through the photovoltaic effect. The first solar cell was developed in the 1880s, and subsequent advancements led to the creation of silicon solar cells in 1954. These early solar cells were less efficient and more expensive than modern counterparts.
As of 2022, over 90% of the solar cell market consists of crystalline silicon cells. Solar panels produce direct current (DC) power, which needs to be converted to alternating current (AC) for practical use, typically accomplished through the use of inverters. Multiple solar cells are connected within panels, and panels are combined to create arrays. These arrays are then connected to inverters, which produce power at the desired voltage and frequency/phase for AC electricity.
In many developed countries, residential PV systems are connected to the grid. In such grid-connected systems, energy storage is optional. However, in some applications, such as satellites, remote areas, or places with unreliable grid access, batteries or additional power generators are added to ensure electricity supply during nighttime and periods of limited sunlight.
Thin-Film Solar Cells A thin-film solar cell, a second-generation solar technology, is created by depositing one or more thin layers of photovoltaic material onto a substrate like glass, plastic, or metal. This technology is used in commercial applications and includes variations such as cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and amorphous thin-film silicon (a-Si, TF-Si).
Perovskite Solar Cells Perovskite solar cells (PSC) are a new type of solar cell featuring a perovskite-structured compound, often based on lead or tin halides, as the light-harvesting active layer. Perovskite materials are cost-effective and easy to manufacture. Laboratory-scale devices using these materials have seen impressive efficiency increases, with some reaching 25.7% in 2021. Perovskite solar cells are regarded as one of the most rapidly advancing solar technologies. Their potential for high efficiency and low production costs makes them commercially appealing, although stability issues remain a research challenge.
Concentrated Solar Power (CSP) Concentrated solar power, also known as concentrated solar thermal, concentrates sunlight using lenses or mirrors and then uses the resulting heat to produce electricity through steam-driven turbines. Several concentrating technologies exist, including parabolic troughs, compact linear Fresnel reflectors, dish Stirling systems, and solar power towers. These systems track the sun and focus light, and they can provide thermal storage for nighttime electricity generation. While CSP contributes a small share of solar power, it is recognized for its potential in energy storage.
Hybrid Systems Hybrid power systems combine solar with energy storage and other forms of generation, such as hydro, wind, or batteries. This combined generation can help stabilize power output and meet varying energy demands. Utilizing existing hydro reservoirs for solar installations is particularly beneficial due to the flexibility and cost-effectiveness of hydropower.
Development and Deployment Solar power has seen substantial growth due to favorable policies and declining module costs. China is expected to lead in new global solar photovoltaic projects by 2024. The early days of solar power saw experiments and developments driven by concerns about the scarcity of coal and other fossil fuels. However, the growth of solar technology was limited in the early 20th century with the dominance of coal and petroleum.
By the 1970s, solar power found application in satellites, but it was considered unrealistic for broader use due to cost constraints. The oil embargo in 1973 and the 1979 energy crisis renewed interest in solar technologies and led to reformed energy policies worldwide.
The evolution of solar power has been influenced by policy changes, economic considerations, and technological advancements, making it a key player in the renewable energy landscape.
Long-Term Savings: Solar panels can generate free electricity for your home for up to 25 years. Over time, this can lead to significant reductions in your electricity costs as energy prices increase.
Environmental Impact: Using solar panels reduces your carbon footprint and contributes to the fight against climate change by using a renewable energy source.
Earn from Excess Power: Your solar system may produce more electricity than you can use at times. This excess power can be exported back to the grid, and you'll get paid for it, reducing your energy costs further.
Energy Independence: Solar panels make your home less reliant on the grid for power, which can enhance your energy security and reduce your vulnerability to power outages.
Financial Incentives: Explore available incentives, such as SEAI grants, to help offset the upfront costs of installing solar panels. These grants can save you money and make the transition to solar power more affordable.
Remember to conduct a solar survey to determine the ideal solar system for your home, and consider factors like your roof's suitability, your budget, energy consumption, and potential for battery storage. Solar panels are a long-term investment that offers both financial and environmental benefits.
SolarShare, Ireland's premier solar panel installation provider, offers a chance to generate up to 80% of your electricity, reduce energy costs, and fight climate change. With state-of-the-art equipment and a commitment to customer satisfaction, SolarShare is your partner in sustainable energy.
Posted by SolarShare on 2023-10-27
Title: "The Evolution and Global Expansion of Solar Power (Mid-1990s to the Present)"
Mid-1990s to 2010 In the mid-1990s, the development of both residential and commercial rooftop solar installations and utility-scale photovoltaic power stations began to accelerate. This surge was prompted by concerns about the supply of oil and natural gas, growing awareness of global warming, and the improving economic viability of photovoltaic (PV) technology compared to other energy sources. The adoption of feed-in tariffs in the early 2000s, a policy that prioritizes renewables on the grid and sets fixed prices for generated electricity, provided investment security and led to a significant increase in PV deployments across Europe.
2010s Solar PV growth was predominantly driven by European installations for several years but has since shifted to Asia, particularly in China and Japan. Additionally, solar power adoption expanded to various countries and regions globally. The largest solar equipment manufacturers were based in China. Although concentrated solar power (CSP) capacity increased significantly, it remained a relatively small portion of the total solar energy landscape. This was primarily due to the substantial 85% reduction in the cost of utility-scale solar PV between 2010 and 2020, while CSP costs saw a 68% reduction during the same period.
2020s Despite rising material costs, including polysilicon, during the 2021–2022 global energy crisis, utility-scale solar power continued to be the most cost-effective energy source in many countries. This was largely due to the increasing costs associated with other energy sources, such as natural gas. In 2022, the global solar generation capacity surpassed 1 terawatt (TW) for the first time. However, the growth of solar generation capacity has been hindered by fossil-fuel subsidies.
Current Status Approximately half of the installed solar capacity is in the form of utility-scale solar power installations.
Forecasts Forecasts indicate that between 2022 and 2027, most of the new renewable energy capacity added will come from solar power, surpassing coal as the largest source of installed power capacity. Utility-scale solar is predicted to become the primary source of electricity in most regions, except for sub-Saharan Africa, by 2050.
According to a 2021 study, the global electricity generation potential of rooftop solar panels is estimated to be 27 petawatt-hours (PWh) per year, with costs ranging from $40 per megawatt-hour (MWh) in Asia to $240 per MWh in the United States and Europe. The realization of this potential will depend on the availability and cost of scalable electricity storage solutions.
Photovoltaic Power Stations A photovoltaic power station, also known as a solar park, solar farm, or solar power plant, is a large-scale grid-connected photovoltaic power system (PV system) designed to provide merchant power. These power stations differ from building-mounted or decentralized solar power systems as they supply electricity at the utility level, serving a wider area or grid, rather than individual users. Utility-scale solar is a term commonly used to describe such projects.
This approach contrasts with concentrated solar power (CSP), another large-scale solar generation technology, which uses solar heat to drive conventional generator systems. Both technologies have their own advantages and disadvantages, but photovoltaic technology has seen broader adoption, accounting for approximately 97% of utility-scale solar power capacity as of 2019.
The capacity of photovoltaic power stations is often rated in megawatt-peak (MWp), representing the theoretical maximum DC power output of the solar array. In some countries, the surface area and efficiency are also specified. However, countries like Canada, Japan, Spain, and the United States often use the converted lower nominal power output in megawatts-AC (MWAC) for better comparability with other power generation forms. Most solar parks have a minimum scale of at least 1 MWp. By the end of 2019, there were over 9,000 solar farms with capacities exceeding 4 MWAC (considered utility-scale), collectively generating over 220 GWAC.
While most large-scale photovoltaic power stations are owned and operated by independent power producers, there is a growing involvement of community and utility-owned projects. In the past, many of these projects were supported by regulatory incentives like feed-in tariffs or tax credits. However, as the levelized costs of solar energy decreased substantially in the 2010s, many markets achieved grid parity, reducing the dependence on external incentives.
Concentrating Solar Power Stations Commercial concentrating solar power (CSP) plants, also known as solar thermal power stations, were initially developed in the 1980s. Notable CSP facilities include the Ivanpah Solar Power Facility (377 MW), the Solnova Solar Power Station (150 MW), Andasol Solar Power Station (150 MW), and Extresol Solar Power Station (150 MW), all located in Spain. The primary advantage of CSP technology is its ability to efficiently incorporate thermal storage, allowing electricity to be dispatched over a 24-hour period. Many CSP power plants use 3 to 5 hours of thermal storage since peak electricity demand often occurs in the late afternoon or evening.
Economics The economic factors for solar power include the costs of modules, support structures, wiring, inverters, labor, land, grid connection, maintenance, and solar insolation specific to the location.
Modules typically have a lifespan of 25 to 40 years, and as such, upfront capital and financing costs constitute a significant portion (80 to 90%) of the overall cost of solar power.
To incentivize and manage the economic aspects of solar power, different countries may implement strategies like price caps or contracts for difference. Solar energy, with its abundant resource and falling costs, has become one of the most cost-effective sources of electricity. In 2020, it emerged as the cheapest source of electricity in many regions. For example, in Saudi Arabia, a power purchase agreement (PPA) signed in April 2021 for a new solar power plant in Al-Faisaliah recorded the world's lowest cost for solar PV electricity production, at just USD 1.04 cents per kilowatt-hour (kWh).
Installation Prices The cost of high-power band solar modules has seen a significant reduction over the years. In 1982, the cost per kilowatt (kW) was approximately $27,000, and by 2006, it had dropped to around $4,000 per kW. Similarly, in 1992, a PV system cost approximately $16,000 per kW, which reduced to approximately $6,000 per kW by 2008.
In 2021, the United States witnessed residential solar costs ranging from $2 to $4 per watt, although solar shingles were notably more expensive. Utility-scale solar costs were around $1 per watt.
Productivity by Location The productivity of solar power in a particular region is contingent on solar irradiance, which varies over the course of the day and year and is influenced by factors like latitude and climate. The output power of a PV system is also affected by variables such as ambient temperature, wind speed, solar spectrum, local soiling conditions, and more.
In various regions, the cost-effectiveness of renewable energy sources varies. Onshore wind power tends to be the most economical source of electricity in Northern Eurasia, Canada, certain parts of the United States, and Patagonia in Argentina. In other parts of the world, particularly in areas with abundant sunshine, solar power often proves to be the most cost-effective choice. Modelling by Exeter University suggests that by 2030, solar energy will be the most cost-effective option in all countries, except for some in northeastern Europe.
The regions with the highest annual solar irradiance are typically found in arid tropics and subtropics, especially in deserts with low latitudes. These deserts receive ample sunshine, often for more than ten hours a day. Notably, these regions are part of the Global Sun Belt, encircling the Earth and encompassing extensive areas in Northern Africa, Southern Africa, Southwest Asia, the Middle East, Australia, as well as smaller deserts in North and South America.
As a result, solar energy is or is predicted to become the most affordable source of energy in Central America, Africa, the Middle East, India, Southeast Asia, Australia, and several other regions.
Self-Consumption In cases of self-consumption of solar energy, the payback time is calculated based on the amount of electricity not purchased from the grid. However, there are instances where the patterns of energy generation and consumption do not align, leading to excess energy being fed back into the grid, which is then sold, and other times when energy is drawn from the grid, which must be bought. The relative costs and prices involved have a significant impact on the economics of self-consumption.
In many markets, the price paid for selling solar electricity back to the grid is notably lower than the cost of buying electricity. This encourages self-consumption. Some regions, such as Germany and Italy, have even offered separate incentives for self-consumption. Additionally, grid interaction regulations have imposed limits on grid feed-in in areas with high PV capacity to enhance self-consumption and reduce electricity wastage.
Enhancing self-consumption often relies on achieving a close match between energy generation and consumption. Batteries or controllable electricity consumption can improve this match. However, batteries can be expensive, and their profitability may require offering additional services besides increasing self-consumption. Hot water storage tanks with electric heating, heat pumps, or resistance heaters can provide cost-effective storage for self-consumption of solar power. Controllable loads like dishwashers, tumble dryers, and washing machines can also contribute to controllable consumption, although their effect on self-consumption may be limited.
The establishment of incentive policies for photovoltaic (PV) technology had its initial political purpose in promoting the growth of the industry, even when the cost of PV was significantly above grid parity. These incentives aimed to help the industry achieve economies of scale and establish itself in the market. Over time, the goals of these policies evolved, focusing on national energy independence, high-tech job creation, and the reduction of CO2 emissions.
Financial Incentives and Variances Financial incentives for photovoltaics vary significantly across countries and even within states in the United States. Various countries like Australia, China, Germany, India, Japan, and the United States offer different financial incentives to promote solar power adoption.
Net Metering Net metering is a mechanism in which the price of the electricity produced by a solar system is the same as the price at which electricity is supplied to the consumer. In this system, consumers are billed based on the difference between their energy production and consumption. Net metering enables homeowners and businesses to generate electricity at one time and consume it at another, effectively utilizing the grid as a massive energy storage system. Surpluses generated during periods of high production are rolled over to the following month. Best practices typically involve the continuous rollover of kilowatt-hour (kWh) credits. Upon discontinuation of service, excess credits may either be lost or compensated at a rate ranging from wholesale to retail or above, including annual credits.
Taxes In certain countries, tariffs, or import taxes, are imposed on imported solar panels. This can impact the cost and accessibility of solar technology in those regions.
Grid Integration Grid integration refers to the management of solar power production within an electrical grid system. Strategies like energy storage and grid energy storage are employed to optimize solar power integration. These methods allow solar power to be dispatched and scheduled to meet demand requirements. For instance, solar power can be stored using thermal energy storage with the use of molten salts, providing a means of energy storage after sunset and during periods of high demand.
Variability Solar power and wind power are considered variable renewable power sources due to their intermittent nature. Traditional generators are capable of adapting to demand, and excess electricity is usually consumed locally or transmitted to other regions. Variability can be a challenge, especially when integrating solar and wind power into the grid, but the degree of difficulty depends on the specific region and its demand patterns.
Energy Storage Energy storage solutions are used to address the variability of solar power. Concentrated solar power plants can utilize thermal storage using molten salts, which are efficient and cost-effective for storing excess solar energy. Stand-alone PV systems often employ batteries to store surplus electricity. Grid-connected systems can send excess electricity to the grid, earning credits that offset electricity purchases from the grid. Batteries are increasingly used to stabilize the electrical grid by managing peak loads and providing electricity when demand exceeds generation.
Common battery technologies used in home PV systems include nickel-cadmium, lead-acid, nickel metal hydride, and lithium-ion. The latter is expected to replace lead-acid batteries due to cost reductions and ongoing development. The potential use of vehicle-to-grid systems, where electric vehicle batteries contribute to grid stability, is also explored. Other rechargeable batteries used in distributed PV systems include sodium-sulfur and vanadium redox batteries, each offering unique benefits in energy storage.
Other Technologies Conventional hydroelectric dams work well alongside solar power, as they can release water from reservoirs as needed. Pumped-storage hydroelectricity is another solution, using solar power to pump water into a high reservoir on sunny days and recovering the energy at night or during unfavorable weather conditions.
Solar and wind power complement each other as they have peak operating times at different hours and seasons. The combination of these sources results in more stable and less variable power generation. In countries with high solar power generation, electricity prices may become negative during peak solar hours, prompting the development of additional battery storage capacity to capture excess energy.
Solar power is recognized for its environmental benefits and potential to mitigate greenhouse gas emissions when replacing electricity generated from fossil fuels. It offers a cleaner and more sustainable energy source. While solar power itself does not produce harmful emissions during operation, its environmental impact is associated with the production of solar panels and the land required for large-scale solar farms.
Production Emissions The manufacturing of solar panels contributes to environmental pollution. A 2021 study estimated that the carbon footprint for manufacturing monocrystalline panels was approximately 515 g CO2/kWp in the US and 740 g CO2/kWp in China. However, this is expected to decrease as manufacturers transition to cleaner energy sources and incorporate recycled materials into production. Solar panels carry an upfront environmental cost, but they offer clean energy throughout their 30-year lifetime.
Life-Cycle Emissions The life-cycle greenhouse-gas emissions of solar farms are relatively low, averaging less than 50 g per kilowatt-hour (kWh). With the addition of battery storage, these emissions may increase to around 150 g/kWh. In comparison, gas-fired power plants without carbon capture and storage emit about 500 g/kWh, while coal-fired power plants emit about 1000 g/kWh. The transition to low-carbon power in the manufacturing and transportation of solar devices can further reduce emissions.
Power Density and Land Use Solar power exhibits a lower power density, averaging around 7 W/m2, compared to nuclear power (240 W/m2) and gas (480 W/m2). However, when considering the land required for gas extraction and processing, the difference in power density between solar and gas becomes smaller. Photovoltaic (PV) systems necessitate more land to generate the same nominal energy output as higher power density sources.
Materials and Recycling Harmful materials are used in solar panel production but typically in small quantities. As of 2022, the environmental impact of perovskite is not fully estimated, with potential concerns about lead usage. Additionally, the demand for materials like copper, tellurium, and indium may increase due to the deployment of large-scale solar projects. Recycling initiatives are being developed to address these material demands.
Reuse and Maintenance Used solar panels are sometimes repurposed in developing countries, such as in Africa. Regulations for the recycling of solar panels are in place in several countries. Solar power systems typically have low maintenance costs compared to other energy sources. Some experts advocate designing solar systems to be more repairable.
Environmental Concerns Solar projects, especially large-scale solar farms, can generate environmental concerns. They have been associated with habitat destruction, posing risks to birds, desert tortoises, Mojave fringe-toed lizards, bighorn sheep, and local flora. Critics have highlighted issues such as habitat displacement and harm to wildlife.
Concentrated Solar Power Concentrated solar power, a small portion of the solar power sector, may require significant water usage, particularly when built in desert regions. This dependency on water resources can be problematic for environmental sustainability.
Solar power remains an essential element in transitioning to clean and sustainable energy sources, but it requires responsible and environmentally conscious practices throughout its life cycle and deployment.
You can start saving as soon as your solar PV panels are installed. On average, you can save up to €800 off your annual electricity bills.
SolarShare was founded in 2019 with a mission to accelerate the transition to a zero-carbon economy. The team, led by Richard O'Rourke, is dedicated to helping communities in the fight against climate change.
SolarShare's management team has extensive experience in the solar energy industry and has successfully installed solar panels in various European homes. They specialize in custom-designing systems for optimal performance.
Solar panels capture sunlight and convert it into electricity. Mounting systems secure the panels to roofs. Inverters transform DC power into AC power. Optimizers boost panel performance. Batteries store unused energy. EV chargers charge electric vehicles. Diverters send excess power to water heaters. Smart system integration manages energy flows efficiently.
By joining the SolarShare movement, you can make a positive impact on the environment, save on energy costs, and become part of a community dedicated to zero-carbon living.