The cost of solar panels have been decreased in the last decades ad it is expected that this trend will continue in the coming years. The efficiency of the current solar panels are somehow low, between 15-25 %, but some research activities could increase this level in the coming decades.

International reference: Solar (US$0.15-US$0.30/kWh). The high cost of these types of renewable energy source is largely due to the high price of silicon crystals. Silicon prices continue to rise as their widespread production applications are leading to supply shortages. However, newly developed alternative materials could bring the cost down below US$0.05/kWh in the near future.

It is extremely important to note the decline in solar PV costs in the coming years. For example, the average price of approximately Wp of solar PV modules, traditionally the most expensive SFV element is:

 Table: Price per Wp of PV modules

2008                           US$4/Wp

2011                            US$2/Wp

2014                           US$0.61/Wp (agosto 2014)

2020                            US$0.35/Wp (expected) 

Cost of major powers investors: Today US$0.15/Wp; in 2020: less than US$0.10/Wp

Cost of metallic structures: Today US$0.25/Wp; in 2020: less than US$0.12/Wp

Wiring cost: The wiring cost is expected to decreases in 2020 due to an increase in the solar PV module efficiency, which has to be 20%.

Current costs and perspectives of PV modules components Si-c: Its costs have declined. Today the range is between US$0.50 and US$0.94 cents/Wp; the average is US$0.61 (September 2014) cents/Wp. Keep in mind that about 60% of world production is multi crystalline silicon modules (poly) and 30% mono crystalline silicon. The costs of multi crystalline modules are lower (average of about US$0.57 cents/Wp). Higher efficiency monocrystalline are more expensive. It is predicted that in the next five years the today average of US$0.61 cents/ Wp, will be less than US$0.40 cents/Wp. 

Investors: The higher power investors are cheaper, between US$0.13 and US$0.15 cents/Wp. Those of lesser powers to smaller systems can reach about US$0.40 cents/ Wp. The medium-term forecast is that costs will continue to decline below the US$0.10 cents / Wp for higher powers.

Structures: The cost of steel structures for systems that support perpendicular winds of 150 km / hour, will decrease as a result of better designs. Its costs have been above US$0.25 cents/ Wp, but there are designs that can take the cost below US$0.12 cents / Wp. With the increase in the efficiency of the modules will decrease the cost of the structures.

Electricity: Includes wiring and other electrical parts of the solar PV system. With the increase in the efficiency of the solar PV modules will decrease the cost of cabling.

Labor: This expenditure is related to salaries and payments by human labor, which is very favorable in the case of Cuba, because the salary is calculated in US$, but payed in Cuban pesos. For example, installers of solar PV systems in developed countries earn US$25 to US$30 per hour, and of course, this cost is much smaller in Cuba.

Operation and maintenance (OM): Solar PV has one of the lowest costs in O&M of all energy sources used for electricity generation, and a large part of it is on salary cost.

Depreciation/Deviation: The most important is the decrease of the initial efficiency of the solar PV module during 25 years of operation, which is 20%, that is, the solar PV panels should be replaced although it is still has an efficiency of 80%. This depreciation takes into account the need to generate an average of 1,360 kWh/ kWp per year (27,200 in 20 years and 34, 000 in 25 years).

Recycling: A new element for solar PV systems that has not being taken into account until now is the decrease in the cost of solar PV systems as a result of the recycling of the solar panels once they met their useful life (25 years). This element should be considered in the future due to the possible reuse of glass, silicon, aluminum and tin. There is no need, in most cases, to a new earth movement, and it is also possible to reuse metal structures supports, at least in the form of steel scrap and aluminum. For this reason, solar PV systems are highly recoverable.

Lifetime of the SPV: On solar PV calculations costs, the number of years of useful life of the module, 25 years, was used as reference. Due to improvement of encapsulation and decreased degradation, that number of years continue to increase. It is expected that within a few years (2020), lifetime of solar PV modules possibly lasting about 30 years, which in turn will further reduce the cost per kWh as compared to the total cost divided by the number of hours; for example, to 1,360 kWh / kWp within 25 years of lifetime correspond to 34,000 peak hour generation, and with 30 years of lifetime the total hours of generation will increase to 48,800 hours.

Efficiency of solar PV modules: Another element that will influence the decrease of the costs of solar PV systems is the increase in the efficiency of solar PV cells and modules; for example, with an increase in the efficiency from 15% to 20%, it will require an appreciable reduction of the area occupied by a similar magnitude of solar PV power.

The cost of solar panels have been decreased in the last decades ad it is expected that this trend will continue in the coming years. The efficiency of the current solar panels are somehow low, between 15-25 %, but some research activities could increase this level in the coming decades.

International reference: Solar (US$0.15-US$0.30/kWh). The high cost of these types of renewable energy source is largely due to the high price of silicon crystals. Silicon prices continue to rise as their widespread production applications are leading to supply shortages. However, newly developed alternative materials could bring the cost down below US$0.05/kWh in the near future.

It is extremely important to note the decline in solar PV costs in the coming years. For example, the average price of approximately Wp of solar PV modules, traditionally the most expensive SFV element is:

 Table: Price per Wp of PV modules

2008                           US$4/Wp

2011                            US$2/Wp

2014                           US$0.61/Wp (agosto 2014)

2020                            US$0.35/Wp (expected) 

Cost of major powers investors: Today US$0.15/Wp; in 2020: less than US$0.10/Wp

Cost of metallic structures: Today US$0.25/Wp; in 2020: less than US$0.12/Wp

Wiring cost: The wiring cost is expected to decreases in 2020 due to an increase in the solar PV module efficiency, which has to be 20%.

Current costs and perspectives of PV modules components Si-c: Its costs have declined. Today the range is between US$0.50 and US$0.94 cents/Wp; the average is US$0.61 (September 2014) cents/Wp. Keep in mind that about 60% of world production is multi crystalline silicon modules (poly) and 30% mono crystalline silicon. The costs of multi crystalline modules are lower (average of about US$0.57 cents/Wp). Higher efficiency monocrystalline are more expensive. It is predicted that in the next five years the today average of US$0.61 cents/ Wp, will be less than US$0.40 cents/Wp. 

Investors: The higher power investors are cheaper, between US$0.13 and US$0.15 cents/Wp. Those of lesser powers to smaller systems can reach about US$0.40 cents/ Wp. The medium-term forecast is that costs will continue to decline below the US$0.10 cents / Wp for higher powers.

Structures: The cost of steel structures for systems that support perpendicular winds of 150 km / hour, will decrease as a result of better designs. Its costs have been above US$0.25 cents/ Wp, but there are designs that can take the cost below US$0.12 cents / Wp. With the increase in the efficiency of the modules will decrease the cost of the structures.

Electricity: Includes wiring and other electrical parts of the solar PV system. With the increase in the efficiency of the solar PV modules will decrease the cost of cabling.

Labor: This expenditure is related to salaries and payments by human labor, which is very favorable in the case of Cuba, because the salary is calculated in US$, but payed in Cuban pesos. For example, installers of solar PV systems in developed countries earn US$25 to US$30 per hour, and of course, this cost is much smaller in Cuba.

Operation and maintenance (OM): Solar PV has one of the lowest costs in O&M of all energy sources used for electricity generation, and a large part of it is on salary cost.

Depreciation/Deviation: The most important is the decrease of the initial efficiency of the solar PV module during 25 years of operation, which is 20%, that is, the solar PV panels should be replaced although it is still has an efficiency of 80%. This depreciation takes into account the need to generate an average of 1,360 kWh/ kWp per year (27,200 in 20 years and 34, 000 in 25 years).

Recycling: A new element for solar PV systems that has not being taken into account until now is the decrease in the cost of solar PV systems as a result of the recycling of the solar panels once they met their useful life (25 years). This element should be considered in the future due to the possible reuse of glass, silicon, aluminum and tin. There is no need, in most cases, to a new earth movement, and it is also possible to reuse metal structures supports, at least in the form of steel scrap and aluminum. For this reason, solar PV systems are highly recoverable.

Lifetime of the SPV: On solar PV calculations costs, the number of years of useful life of the module, 25 years, was used as reference. Due to improvement of encapsulation and decreased degradation, that number of years continue to increase. It is expected that within a few years (2020), lifetime of solar PV modules possibly lasting about 30 years, which in turn will further reduce the cost per kWh as compared to the total cost divided by the number of hours; for example, to 1,360 kWh / kWp within 25 years of lifetime correspond to 34,000 peak hour generation, and with 30 years of lifetime the total hours of generation will increase to 48,800 hours.

Efficiency of solar PV modules: Another element that will influence the decrease of the costs of solar PV systems is the increase in the efficiency of solar PV cells and modules; for example, with an increase in the efficiency from 15% to 20%, it will require an appreciable reduction of the area occupied by a similar magnitude of solar PV power.

Jorge that is a very detailed and well laid out answer. Might i ask where are you getting your numbers from?  

I hope you find your answer at this link http://energyinformative.org/cheapest-best-value-solar-panels/

Hello I took a course a few months about renewable energy, with international companies that develops and finance solar energy projects, and the total cost of the cheapest solar panel “INSTALLED” was around 2.5 to 3.o USD.

And the end in a solar energy project the persons are looking the lesser payback time. So for that reason mono-crystalline panels are used, because the cost per W is small, and its price are reducing even more every year, because there are many companies producing this kind of panel.

Dear George. Some of this information can be found in two of my books listed in RG on renewable and a paper prepared by Prof Stolik from Cuba.

Dear George,

It is sometimes not enough to have an efficient solar panel because if its mode of construction is in such a way that it is not suitable for use in your climate, then the efficiency would only be part of the whole story. For example, if the efficient PV module is encapsulated in glass on both sides and you intend to use it in a warm climate, then it might suffer loss of efficiency more than a less efficient module that can produce more energy under the same climate. Such limitations are not only restricted to glass but to the mode how the PV cells are encapsulated, how much space there is between them, etc...

But to come back to your question, the standard modules on the market have rleatively similar efficiency 16-18% but some variation in price, due to finishing touches and ALSO the quality fo the solar cell itself. Therefore, my answer is that cheap modules that are currently in the market may not last as long as a more carefully finished product (e.g. sealing at the edges, type of glazing on facade - reflective or non-reflective, etc..). 

thanks

Solar Cell  characterize by Energy efficiency, energy pay back period and return of investment, give different choice between single crystal, multi-crystalline, thin film and nano tube solar panel. The cost of technology and product are regional specific parameters. So its need to identify location first. The cost of Solar Cell is decreasing at very fast curve. 

Thanks to all for sharing valuable information 

Dear Sivanandam,

Solar paint (made from nano scale solar cells with paint) is coming which is cheaper and efficient. check the link