On Internet we can find free tools for basic or low complexity solar systems dimensioning and for certain components or accessories estimation.

Sopelia research team has carried out an exhaustive search and testing from which a new corporate website section called Free Solar Tools has been created.

Selected tools were classified into 4 categories.

Today we will analyze the first one: Solar Resource and Other Baseline Data.

In this category we will find data about solar resource and other variables to consider in order to estimate the energy that solar system will provide in our location.

It is the starting data for necessary solar system dimensioning in order to satisfy our energy demand.

Tools order is not random. We have prioritized the most intuitive, the most universal and those that can be online used without download.

For this first category our selection is the following:

1) Meteorological and solar energy data

Sponsored by NASA Science Applications Program and developed by the World Prediction Energy Resources Project, this site offers information and supporting documentation for solar systems dimensioning. The “Data Retrieval” section that interests us is “Meteorology and Solar Energy” and within it, “Data Tables for a Particular Location”. Once there, entering Latitude and Longitude of our location, we access a series of calculation parameters that we can select or obtain entirety.

2) Daily and annual solar calculator

Spreadsheet developed by US NOAA Earth System Research Laboratory based on Jean Meeus astronomical equations algorithms. It allows to calculate solar day, year and location specific data.

3) Renewable energies Global Atlas

Geographic Online Information System (GIS) interrelated worldwide distributed centers data. In addition to information about renewable energy resources you can access information such as population density, topography, land use, infrastructure and protected areas. The objective of this system is to allow users to identify areas of interest for further exploration. It is an initiative that involves national institutes, energy agencies, private companies and international organizations.

4) Opensolar

Open database (you can extract and insert information) with global average daily solar radiation data for each month of the year measured on the surface.

5) Monthly average radiation calculation

Tool developed by IDEA research group to calculate monthly average radiation on arbitrarily oriented and inclined surfaces.

Accessing Free Solar Tools section of Sopelia’s corporate website you will find the links to get these tools and begin to configure your future solar system.

Solar energy wherever you are with Sopelia.

We are witnessing an unprecedented growth of renewable energies participation in global energy matrix.

But why does the average citizen not perceive the benefits and feel somehow alien to this process ?

The main reason is that this participation is built on an already obsolete energy matrix paradigm.

The 3 pillars of the future energy matrix are:

1) Energy efficiency

In this element the consumer is the variable of greater weight.

The transformation is related to a energy consumption habits profound change. It is very difficult to happen in those countries with a high subsidy component in their energy tariffs.

The other important aspect and on which the states can directly act is the stimulus for more efficient devices acquisition.

The energy efficiency generates a lower demand and therefore a decrease of generation investment.

2) Renewable energies

In energy-importing countries (mostly in Latam) renewables development is an instrument to improve payments balance.

In any world country, a means to boost and make the economy more competitive.

Investment in a solar system is very high in countries that do not manufacture equipment compared to those that do.

Let us illustrate this with a concrete example: in the largest producer of solar modules (China) W FOB value is around US$ 0.50. That solar module placed outside destination country customs, for example Argentina, costs US$ 1.20 (+ 140%). If we add the commercial margin of the companies that sell and the companies that install them, the final consumer ends up paying US$ 2.50 / W (+ 400%).

The companies awarded renewable energy public tenders in countries where no equipment is manufactured do not pay import taxes for equipment and are exempt from most taxes.

It is a utopia the idea of short and medium term local equipment manufacturing if the country does not have the capacity to convert silicon to solar-grade silicon or technology to manufacture evacuated vacuum tubes. Especially if we consider the aggressive decrease in solar equipment price of last 5 years.

3) Distributed generation

Distributed generation systems surpass those of centralized generation in national security (attacks, warlike conflicts, etc.) and supply continuity (natural catastrophes and seasonal peaks cuts) questions.

Distributed generation is also a wealth redistribution way, giving consumer the opportunity to generate the energy he consumes and the possibility of obtaining an income from the surplus.

New energy infrastructure investments should be directed towards interconnecting and renewables integrating systems and abandoning the paradigm of an already obsolete energy matrix (distribution from centralized generation plants).

Efforts to develop large wind and solar generation should be redirected to distributed generation systems development.

Large plants should be only a complement, located only in locations where renewable resource potential is very high and take advantage primarily of rooftop and ceilings surface instead of being placed in soils that could have other uses.

Fingers and toes are enough to count worldwide renewable sector EPC companies of a certain scale projects.

These companies are itinerant. They land in countries with great potential where the ban is lifted.

In Europe the main countries of the itinerary were Spain, France, Italy and now United Kingdom.

In Latin America they went to Chile, Brazil, Mexico and now Argentina.

The myth that this type of projects generates a large number of stable jobs is false. The work is intensive only at construction time. Then the operation and maintenance of these plants is relatively simple and is done remotely with very little personnel on field.

We are not against renewable generation plants development, what we manifest is that the energy matrix paradigm is the one that is already obsolete.

The renewable resource generates energy where it is available. If we take advantage of it there, we avoid all expenses and eliminate all energy losses inherent to the distribution of that energy.

Stable jobs generation and sustainable economic renewable sector development go hand in hand with distributed generation and prosumer (residential, industrial and services) figure development.

Solar is the ideal renewable energy for distributed generation because it has the highest integration into urban environment level.

Countries that take the following steps to achieve the future energy matrix, will make their economy more competitive:

• Stimulating efficient devices acquisition (special financing, tax exemptions) or taxing non efficient devices acquisition

• Eliminate import taxes on renewable equipment inputs that cannot be manufactured in the short and medium term and focus industrial effort on imported inputs supplemented with local raw material inputs

• Give priority to distributed generation and prosumers creation over large generation power plants development

• Invest in interconnection and renewables integration energy infrastructure and gradually abandon the obsolete energy matrix (large power systems – distribution).

It is a long process but, like every great journey, it begins by taking a step.

Municipalities (in solar thermal energy) and Provinces (in photovoltaic solar energy) have the power to promote solar distributed generation development.

There are examples on which they can work to adapt to each local reality and to introduce improvements to avoid mistakes.

In distributed solar thermal energy, an example can be the Spanish Technical Building Code (CTE). An improvement to introduce to this referent could be the obligation of a periodic maintenance to verify the system good operation and to corroborate solar fraction required is reached.

In distributed photovoltaic solar energy, an example may be the net-metering regime of some US states (eg California). In this case, the implementation of complementary financial tools (special financing, leasing), that have promoted its great development, could be imitated.

Conditions (political and economic stability) must be created for desired events to occur.

Reality cannot be modified by laws.

For example, if a Latin American province has regulations to promote distributed generation since 2013 and in 3 years have connected 10 systems, it means that we are doing something wrong.

As in all life aspects of any individual or society, goals must be set (ambitious but at same time achievable) in order to achieve success, deadlines must be set and periodic measurements must be made to introduce improvements and correct errors.

This is very difficult if long-term energy policies that surpass current government are not adopted.

For now, short term rules.

It is easier to sit down with a few to negotiate and cut tapes for the photo, than work seriously and in the long run for general interest.

Solar energy wherever you are with Sopelia.

Solar energy is the energy obtained by capturing light and heat emitted by the sun.

Radiation power varies by time of day, weather conditions and latitude.

It can be assumed that a good surface radiation value is about 1000 W / m².

This power is known as irradiance.

Radiation is usable in direct and diffuse way, or the sum of both components.

Direct radiation comes directly from the solar focus, without intermediate reflections or refractions.

The diffuse is issued by the daytime sky thanks to the multiple reflection and solar refraction phenomena of the atmosphere, clouds and other atmospheric and terrestrial elements.

Direct radiation can be reflected and concentrated for use, while it is not possible to concentrate the diffused radiation coming from all directions.

Albedo radiation is reflected by the bodies located around the surface on which we want to assess the radiation.

The amount of energy due to sunlight direct radiation an exposed surface can intercept depends on the angle between the ray and the surface in question.

If the surface is perpendicular to the rays, this value is maximum, decreasing as the angle does.

The intensity on the surface varies in the same proportion as energy does.

This tilt effect is the reason why sunlight heat much more up at noon than in early morning or late afternoon.

It is also the reason why high-latitude regions (near the poles) received much less energy than the closest to Ecuador.

Solar coordinates used to determine Sun position referred to the horizontal plane are two:

• Solar Height (h) which is the angle between the sun’s rays on the horizontal surface. The zenith angle is the rays angle with the vertical, that is, the complement of the height.

Solar height (northern hemisphere perspective)

• Azimuth (A) which is the Sun angle rotation measured on the horizontal plane through the ray projection on said plane and taking as origin the North if we are in the southern hemisphere.

By convention, the azimuth is considered negative when the sun is to the east (morning) and positive when placed to the west (after noon).

Azimuth

The theoretical number of sunshine hours is time length between sunrise and sunset.

In these 2 times the height of the sun is zero.

The number of sunlight hours depends on the geographical point considered and the time of year.

During the summer, the sun makes a very wide and high trajectory on the sky and is long over the horizon. The opposite happens in winter.

Path of the sun in different seasons (southern hemisphere perspective)

At solar noon (instant when the azimuth is zero), the sun elevation is maximum and shadows length minimun.

The shadow on the floor of a vertical rod coincide with meridian (South-North) direction, which must be accurately determined, for example, to correctly orient solar collectors or modules.

The most important factor influencing the amount of incident solar energy on a location or particular area is cloudy days ratio that occur each year.

This content is extracted from “Introduction to Solar Energy” ebook sold exclusively at Amazon.

Solar energy wherever you are with Sopelia.