Tag Archives: renewable energies

The Real Energy Revolution

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.

Resultado de imagen de eficiencia energética

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.

Resultado de imagen de energías renovables

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.

Resultado de imagen de generación distribuida

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 Thermal Energy

Solar thermal energy systems for domestic applications will be increasingly present in the built landscape and will be promoted by regulations such as solar ordinances or future building technology standards.

The most basic system is the compact equipment called thermosiphon, which incorporates all subsystems and where the fluid circulates naturally (difference in densities).

Resultado de imagen de termosifón solar

Solar thermal systems use the sun’s rays to get hot water or air.

Special plates, called collectors, concentrate and accumulate Sun heat and transmit it to the fluid we want to heat.

This fluid can be home’s drinking water or home’s heating or cooling hydraulic system.

Generally a thermal solar energy system is constituted by several subsystems, which in turn can be considered as interdependent systems connected to each other.

However, sometimes the same physically independent element performs several functions within the solar system.

These different subsystems are:

a) Capture system: composed of solar collectors. They are responsible for receiving the solar radiation and transmit it to the fluid that circulates inside.

Imagen relacionada

b) Accumulation system: composed of one or more deposits to accumulate the hot water generated up to the moment of its use.

Resultado de imagen de tanque solar térmico

c) Hydraulic system: composed of the pumps and pipes through which the working fluid circulates. A primary circuit transports the energy captured to the accumulator. The circulation of the fluid through the pipes is performed by a circulation pump or by natural circulation.

Resultado de imagen de circuito solar térmicod) Exchange system: exists in case the fluid flowing through the solar collectors is not the same as the one used by the user; for example when there is frost risk or user fluid can damage the solar system. The exchanger can be part of the same accumulator or located outside.

Resultado de imagen de intercambiador solar

e) Control system: in pumps forced circulation systems will be in charge to start and stop them. Different components system actuation (motorized valves, pumps, etc.) is done through control mechanisms.

Resultado de imagen de centralita solar térmico

f) Auxiliary energy system: generally solar system economic viability requires that total energy demand cannot be met with solar input at all times. The energy produced by solar system depends on climatic conditions and that is why an auxiliary energy production system is available. These support equipment complement the solar system in order to ensure at all times hot water service continuity.

Resultado de imagen de caldera gas

Solar thermal systems have a great similarity with conventional thermal systems.

In fact, they share all their components (pipes, protection mechanisms, accumulation tanks, exchangers, pumping groups, insulation) except one: solar collectors.

This content was extracted from Solar Thermal Energy Technical & Commercial Manual and is part of Solar e-learning.

Solar energy wherever you are with Sopelia.

Solar Layout (PV)

Solar Layout is the App for collectors and solar modules on site positioning.

This is the most intuitive Solar App of the market.

To use it on field is not necessary to have an Internet connection because it works from place latitude, obtained by GPS.

Today we will see PV solar energy part.

To begin press right command represented by the figure of the house with the solar module and cable with the plug in the initial screen.

fig-1

If our Smartphone GPS is not enabled, the App will ask us to activate it to locate our position.

Intermittent earth planet image immediately appear with the legend “Localizing”.

When our device GPS have located our position, the following screen appears to confirm it.

fig-2

By confirming our location Solar Equipment Use Menu will display.

In the same we find 4 applications:

1- Winter use: represented by the snow image
2- All year use: represented by flower, sun, leaf and snow images
3- Spring / summer use: represented by flower and sun images
4- On-grid connection: represented by the plug image.

fig-3

By selecting one of the 4 applications, Options Menu will display.

There are 3 variables in the Menu:

1- Inclination: represented by module and angle image
2- Orientation: represented by module and cardinal points image
3- Distance: represented by 3 modules rows image.

fig-4

By pressing Inclination option, we get recommended inclination value for location and solar application selected, accompanied by some Tips considering losses to take into account.

fig-5

Pressing Orientation option, we obtain procedure to fix modules orientation description and access to recommended compass App discharge, if we don´t have it.

fig-6

Pressing Separation option, the Kind of Surface Menu is displayed for us to select the appropriate option (Horizontal / Non horizontal).

If the surface on which the modules will be placed is horizontal, we only must enter Collector Height in cm data.

fig-7

If the surface on which the modules will be placed is non horizontal, in addition to Collector Height in cm data, we must enter Surface Inclination Angle data.

We will enter a positive value if it matches the modules inclination direction and a negative value if it is different.

fig-8

In this way we obtain the Separation (distance) between modules rows in meters.

fig-9

Pressing i button Tips related to shadows and singular locations (snow, desert and rain areas) are deployed.

Download Solar Layout and placed solar PV modules on site in the most intuitive way with Sopelia.

Solar El Salvador

In the central region of El Salvador solar irradiation is high (5.3 kWh / m2 / day) compared to other locations such as Germany or Tokyo (3.3 kWh / m2 / day).

The solar irradiation map in El Salvador was created under the SWERA project, which shows the solar irradiation potential in a one year daily average.

Resultado de imagen de energía solar el salvador

In last years the country began to work in the energy matrix diversification introducing renewable sources participation.

According National Energy Council figures at the end of 2015 the country had an installed capacity of 1,659.6 MW. Of these, about 46% is thermal generation (fossil fuel), 28.5% is hydroelectric, 12.3% is geothermal and 13.6% is generated from biomass.

In March 2015, from a partnership between a Taiwanese company and a local oil group emerged a Salvadoran company that set up a solar panel and LED light production plant.

The plant is located in San Juan Opico and becomes the first high-tech devices assemble plant in El Salvador.

In October 2015, Legislature approved Fiscal Incentives Law reforms to promote renewable energy use, reduce greenhouse gas emissions and improve national payments balance through fossil fuels imports reduction.

The reform affects 4 articles of the Law and is specified in:

– Inclusion of marine and biogas renewable sources, adding them to those already specified in article 1 (hydro, geothermal, wind, solar, biomass)

– Elimination of 20 MW limitation to be subject of tariff duties payment exemption for 10 years

– 5 years income tax exemption for more than 10 MW projects, maintaining 10 years term for equal or less than 10 MW projects.

In addition, it extends deadlines for SIGET to decide on project certification and the Ministry of Finance to issue tax benefits agreement to 45 business days.

Also included expansion of existing renewable generation plants as eligible projects.

In February 2016 DELSUR Electricity Distributor and regulators announced a new bidding process for 150 MW of wind and solar photovoltaic generation for 20 years from 2019.

This process begins with participatory consultation phase so that everyone can access bidding rules and make comments they deem necessary.

The resulting document must be approved by SIGET and then made available to potential bidders.

It is estimated that this new renewable energy projects bidding process will generate an investment of around U$D 300 million over the next two years and will be able to supply 250,000 households demand.

This is the second bidding process carried out for projects with these technologies installation and generated energy in the wholesale market commercialization.

Resultado de imagen de energía solar el salvador

The first process culminated successfully with 94 MW of photovoltaic technology award, which will start supplying in 2017.

The process will be coordinated by DELSUR, with the support of the rest of the country’s electricity distributors, governmental and private entities, among others.

The development of high temperature solar thermal systems has also been considered.

Studies indicate that the potential of this type of energy is high in El Salvador and, although the initial investment cost is still high, there are future development plans for concentrated solar energy.

Solar energy wherever you are with Sopelia.

The Solar Energy

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.

Resultado de imagen de altura solar

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).

Resultado de imagen de azimut solar

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.

Resultado de imagen de trayectoria del sol y estaciones

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.

Ecuador Solar PV

Ecuador is in a prime location in terms of solar resource, being almost perpendicular the radiation received, unchanged during the year and with a constant angle of incidence; characteristics that give enormous potential for photovoltaic use.

Ecuador’s solar market has developed mostly in isolated facilities for rural electrification until recently.

The first photovoltaic grid connected plant is located in the northern province of Imbabura, with 998 kW nominal power.

Resultado de imagen de fotovoltaica imbabura

To boost photovoltaic generation, in 2012 Conelec renovated 04/11 regulation and set a preferential rate of U$D 0.40 per kW / h of generation.

Under that legislation, in January 2013, the Conelec signed permits for domestic and foreign enterprises to build 355 MW of photovoltaic energy in 91 projects (15 greater than 1 MW and 76 less than 1MW).

The granting of these permits received numerous criticisms of sectors stated that rate was too high compared to hydroelectric generation cost or the same photovoltaic in other countries of the region.

The Conelec revoked building permits of several projects because concessionaires failed to meet construction schedules because funding lack. In some cases because works were started without studies or authorizations.

Representatives of some projects construction companies said that delays and permits revocation were due a number of construction bureaucratic obstacles, in addition to lack of funding.

Initially, the National Finance Corporation (CFN) announced that would finance such projects, promise did not materialize.

Companies that completed their projects said they had no problems with control entities and requested they be allowed to take over the unfinished projects.

The stark reality is that by the end of 2013 operated in Ecuador 4 MW photovoltaic.

During 2014 new PV installed capacity was 22 MW, bringing the installed capacity in 26 MW in early 2015.

The accumulated installed capacity stagnated below 30 MW since during 2015 virtually no photovoltaic MW was added in the country.

Given that in January 2013 agreements for over 300 MW photovoltaic projects were closed, it is clear that progress is much slower than initially expected.

Resultado de imagen de fotovoltaica ecuador

Ecuador does not have a framework to regulate and promote the photovoltaic distributed generation.

According to the 2015 National Energy Balance, electricity generation corresponds to 45.6% hydropower; 0.3% wind energy; 0.1% solar energy and 1.6% biomass energy.

Solar energy in Latam with Sopelia.

Solar Layout (Thermal)

Solar Layout is the App for collectors and solar modules on site positioning.

This is the most intuitive Solar App of the market.

To use it on field is not necessary to have an Internet connection because it works from place latitude, obtained by GPS.

Today we will check solar thermal energy part.

To begin press left command shown in initial screen with the house, the solar collector and the user taking a hot shower.

fig-1

If our Smartphone GPS is not enabled, the App will ask us to activate it to locate our position.

Intermittent earth planet image immediately appear with the legend “Localizing”.

When our device GPS have located our position, the following screen appears to confirm it.

fig-2

By confirming our location the Solar Equipment Use Menu displays.

There are 3 applications in the Menu:

1- Hot water: represented by a shower image
2- Heating: represented by a radiator image
3- Outdoor pool conditioning: represented by a pool ladder image.

fig-3

By selecting one of the 3 applications, Options Menu will display.

There are 3 variables in the Menu:

1- Inclination: represented by collector and angle image
2- Orientation: represented by collector and cardinal points image
3- Distance: represented by 3 collectors rows image.

fig-4

By pressing the Inclination option, we get recommended inclination value for location and solar application selected, accompanied by some Tips considering collector type used.

fig-5

Pressing Orientation option, we obtain description of procedure to fix collectors orientation and access to recommended compass App discharge, if we don´t have it.

fig-6

Pressing Separation option, the Kind of Surface Menu is displayed for us to select the appropriate option (Horizontal / Non horizontal).

If the surface on which the collectors will be placed is horizontal, we only must enter Collector Height in cm data.

fig-7

If the surface on which the collectors will be placed is non horizontal, in addition to Collector Height in cm data, we must enter Surface Inclination Angle data.

We will enter a positive value if it matches the collector inclination direction and a negative value if it is different.

fig-8

In this way we obtain the Separation (distance) between collector’s rows in meters.

fig-9

Pressing i button Tips related to shadows and singular locations (snow, desert and rain areas) are deployed.

Download Solar Layout and placed solar thermal collectors on site in the most intuitive way with Sopelia.

Solar Municipality Manual

In September 2014 we sent to General Pueyrredón Municipality government in Argentina a draft with proposals.

It was proposed energy efficiency and increased use, promotion and development of solar energy at municipal level.

We believe it can serve as reference for those municipalities that are not using their solar resource and want to start doing so.

The proposals include the following assumptions / premises:

I) Economic evaluation (initial investment, annual savings and investment recovery period) of energy efficiency measures to be applied and solar energy systems to incorporate.

II) Energy efficiency and solar energy promotion to improve environmental quality, develop a new economic sector and new jobs creation in the Municipality.

III) Academic, business and institutional sectors participation.

Resultado de imagen de eficiencia energética

1.1) Energy Efficiency Proposals

1.1.1.) Public buildings audit to identify areas in which implement energy efficiency measures.

1.1.2) Public buildings whose roofs can be used to install solar thermal collectors and photovoltaic modules relieving.

1.1.3) Facilities with intensive lighting use (more than 8 hours / day) relieving to evaluate luminaire replacement by LED, which can achieve savings ranging from 50% -80%. Evaluate motion detectors installation in transit areas and other lighting devices optimization measures.

1.1.4) Evaluate replacement of boilers and air conditioners equipment by biomass, solar thermal and heat pumps, which can achieve between 40% -60% savings.

1.1.5) Installing saving systems (aerators, valves, low consumption taps, etc.) and water reuse (rainwater recovery, rainwater infiltration, etc.) in public buildings and encourage its use in private sector.

Resultado de imagen de energía solar térmica

2.1) Solar Thermal Energy Proposals

2.1.1) Use of solar thermal energy compact equipment to provide hot water to houses in social housing programs and new developments.

2.1.2) Use of solar thermal collectors (flat and vacuum tube) with heat transfer fluids, heat exchangers and independent accumulation tanks; to obtain hot water in public buildings and municipal pools conditioning.

2.1.3) Use of solar thermal systems for new construction public buildings and facilities conditioning.

Resultado de imagen de energía solar fotovoltaica

3.1) Solar PV Energy Proposals

3.1.1) Use of solar photovoltaic systems for lighting and electrification of schools, medical centers, police stations and residential users in isolated localizations. 50W to 400W systems.

3.1.2) Implementation of photovoltaic solar energy in signs (sea, rail, road and air) and parking meters renovation or modernization.

3.1.3) Assess solar photovoltaic energy incorporation in OSSE and other municipality’s departments for:

– Water supply
– Water pumping / irrigation
– Cathodic protection
– Remote satellite systems, fire detection, telemetry and other systems that must provide services in remote or inaccessible places.

20W-50W (emergency kits), 100W-400W (repeaters) and more than 20 Kw (block valves).

3.1.4) Street lighting. Solar lamp with led proof in place to designate (industrial park, municipal office, etc.)

3.1.5) Photovoltaic grid connection project presentation for programs like GENREN (Ministry of Energy).

Resultado de imagen de sostenibilidad largo plazo

4) Long Term Policies

Municipality proposals within Emerging and Sustainable Cities Initiative framework.

4.1) Training

4.1.1) Renewable energies training activities development aimed at agents involved, whether installers, designers, professionals or companies; as it is one of the decisive factors linked to the continuous technology development.

4.2) Urban and Public Facilities

4.2.1) Implement the evaluation of solar technology architectural integration potential in facades and solar passive architecture principles application in new construction public buildings.

4.2.2) Provide treatment to solar ordinance proposal jointly presented by Puerto Hueche S.R.L. and the Clean Energy Research Group, UNMDP Law Faculty.

4.2.3) Public Lighting. Implementing solar and solar / wind street lighting utilization evaluation in all new developments making in each case the comparison with grid-connected conventional lighting system complete work needed.

4.3) Industry

4.3.1) Assess solar thermal energy equipment manufacturing feasibility in Municipality territory, considering that in Industrial Park related equipment manufacturers (heating and cooling) already exist.

4.3.2) Assess PV kits and PV lighting devices mounting feasibility. Synergy with UNMDP (Engineering Materials).

4.3.3) Promote the use of solar thermal energy in industrial sectors with practical applications:

* Brewing and malt
* Textile industry
* Liquid baths automotive paint cleaning and degreasing
* Food industry
– Hot water production for bottles cleaning and disinfecting
– Meat products, canned vegetables and canned fish washing, cooking, blanching and cleaning
– Canned sterilization
– Animal slaughter facilities cleaning.

And in service sector. Some examples:

– Hotels
– Urban waste collection and treatment
– Supermarkets and hypermarkets
– Laundry, carpets cleaning, upholstery, dry cleaners, etc.
– Car repair garages
– Glass containers recovery and reuse.

Solar energy development policies implementation with Sopelia.

Solar Mobile Tool

Sergio came to potential client Mary´s home and asked to see the roof where the solar installations would be located.

Once up, Sergio began to manipulate his mobile phone.

“Do not bother,” Said Mary … “there is no coverage.”

This did not stop Sergio because his tool works based on the location of the mobile device through GPS positioning (internet connection is not required).

From location latitude all calculations are performed.

Sergio selected Solar Thermal Energy from Installation Type Menu first.

Then he confirmed the location on the Map and selected Heating from Installation Use Menu.

Resultado de imagen de inclinación panel solar

The inclination angle of the thermal collectors depends on the use of solar equipment.

Sergio query his mobile, getting the result and informs Mary that 50◦ is the optimal solar thermal collector’s inclination.

Mary, a little surprised, asked what would be the optimum orientation.

“The optimum orientation of the solar collectors is towards the Ecuador” tells Sergio.

Resultado de imagen de orientación panel solar

For guidance, Sergio used Compass App recommended by his tool that has cautiously already downloaded in his mobile.

The last missing data: separation between thermal collector’s rows.

Because surface was horizontal, only data needed was solar collector height in cm.

Sergio query his mobile, get the result and tells Mary that 4.42 m is the minimum spacing between rows.

Totally surprised, Mary tells Sergio where the solar photovoltaic installation would be located.

Sergio selected Solar Photovoltaic Energy option in the Installation Type Menu now.

Then he confirmed the location on the Map and selected On-Grid Connection from Installation Use Menu.

Sergio query his mobile, get the result and tells Mary that 34▫ is the optimum inclination for photovoltaic installation.

As in this case the module rows would be placed on a non horizontal surface, Sergio consulted Mary inclination of that roof sector, which is 20◦.

Sergio entered deck inclination angle from horizontal with a positive value because cover inclination direction coincides with modules inclination.

Finally Sergio told Mary numerous Tips available at i App button to consider for collection surface setting.

Sergio made a very good impression on Mary and demonstrated professionalism.

This App exists, was developed by Sopelia R+D+I and its name is Solar Layout.

Mary´s satisfaction was complete when Sergio told her how could download Solar Layout on his mobile and, in a very intuitive way, get herself recommended values at any geographic location.

Solar Hydraulics

Hydraulics is the physics field that studies fluid mechanics and is divided into Hydrostatic (liquids at rest) and hydrodynamics (liquid in motion).

density of a body d is called the mass m and volume V ratio:

d = m / V

specific gravity pe is the weight (= m g.) and volume ratio:

pe = m. g / V

Fluids (liquids and gases) always exert a pressure pr in all directions.

The pressure is the quotient between a force f (the exerted by the fluid) and the surface area S acted upon by this force:

pr = f / S

The pressure unit in the SI is the Newton divided by m2 (N / m2) and is called pascal.

Pressure exerted by gravity and the forces tending to compress the fluid is called static pressure.

The pressure resulting from movement of a fluid is called dynamic pressure.

Knowing the density or specific gravity of a fluid we can find the static pressure due to gravity at any depth h from either of the following two formulas:

pr = d. g. h

pr = pe. h

Resultado de imagen de presión estática en líquidos

The pressure difference is equal to the depths difference h between 2 points or vertical distance between them.

A typical static pressure, is the atmospheric pressure produced in all directions on the bodies placed on earth surface due to the large air column above them. The result of this all directions atmospheric pressure action produces no net force pushing the body to one side, tends to compress it.

In the case of a container, the atmospheric pressure acts inside and outside and therefore their actions cancel each other.

We are interested in knowing the excess pressure above atmospheric pressure that may be inside the container (tanks or pipes) through measuring devices (manometers).

If air can freely enter and leave a container through the edge of the lid, the liquid surface will only be subjected to atmospheric pressure. It is an open or non pressurized reservoir.

If we measured pressure at different heights in the tank with a manometer it will be equal to zero at the surface and maximum at the bottom.

If the container is now sealed and subjected to additional pressure p, transmitted through the pipes that communicate with distribution circuit; the measurement is equal to the previous one but increased in the value of p. Usually the small pressure difference caused by the height difference is negligible compared to the overall circuit pressure p.

Archimedes’s theorem allows us to know a body weight when it is immersed in a liquid.

This theorem can be applied to a same liquid portion.

Suppose that a liquid portion suffer a slight temperature increase relative to other liquid parts.

Bodies expand by its temperature increasing and when increasing its volume density decreases as mass remains unchanged.

Resultado de imagen de presión estática en líquidos

If d1 is the new density of the portion considered (d1 < d):

Weight of the liquid portion: p = m. g = V1. d1. g

Thrust acting on the liquid portion: E = V1. d. g

Where V1 is the volume of the liquid portion

Resultado de imagen de termosifón

These are the called fluids natural convection currents, in which hot parts tend to rise. Natural circulation or thermosyphon systems are based on this phenomenon for supplying hot water by solar collectors.

This content is part of “Solar Energy Introduction” eBook and solar e-learning of Sopelia.