Six Common Mistakes PV Installers Make!

Mistake #1 

I learned that solar PV panels lose their efficiency as they get hotter, but I also know that solar thermal collectors use water heated by the sun for use in the home. I could just use the water to cool the PV panels and then it would be heated for hot water use. I’m a genius! 

The Truth:

I don’t blame anyone for thinking this. I know I did at first, as I’m sure 90 percent of people learning about solar energy have. The truth is that the math doesn’t work out. In order for your hot water to be sufficient for uses such a showering and washing dishes, it should be in the tank at 120 degrees Fahrenheit, which means it would have to be 130 degrees on the roof and the solar panels would have to be 140 -150 degrees. This is a far cry from the optimal temperature of most solar PV brands at 77 degrees. So, either you’ll be showering in cold water or you’ll be waiting an awfully long time to get a return on those inefficient solar panels (which you’ll need to combat the 140 degree temperature outside). 

Mistake #2 

I’m just going to install a small stand alone system to power one or two things, like the air conditioning and refrigerator. 

The Truth:

AC and refrigeration are the two biggest energy users in a home. A small system not tied to the grid would have a lot of trouble running the AC and refrigerator consistently. If you’re going to install a small standalone system, connect it to smaller end uses, such as the computer, TV, or lighting fixtures. There is nothing wrong with a small system, but having it grid-tied can help tackle those big energy users while keeping the consistency you want. 

Mistake #3 

It seems like the competition is over-charging for installations. I just checked the prices of solar panels and they’re dropping like stones. 

The Truth:

The truth is that while the costs of panels themselves have dropped tremendously in recent years, the installation costs have only dropped slightly. There are plenty of other materials that go into a solar installation that you will need (and be expected to supply). The racking, DC disconnects, heavy gauge wiring and other BOS (balance of system) hardware can add up to more than the panels themselves – making the real installation costs close to where you notice the competition (and don’t forget about your labor). These are simply expenses that you cannot overlook, solar PV systems are dangerous and the safety for yourself and the homeowners could be compromised if you buy cheap or faulty auxiliary components. 

Mistake #4 

Wait, what!? How is a 3 kw system supposed to make a dent in a house that uses 600 kw each month? 

The Truth:

Kilowatts are a measure of instantaneous electricity generation (e.g. right now your system is producing 3 kw), while kilowatt-hours are a measure of cumulative electricity usage/generation over time (e.g. your system produced 8 kwh of solar power today, and your home used 16 kwh of power to run its appliances). When referring to solar PV system capacity, the term kilowatt is usually used – this indicates the ‘peak’ capacity of the panels or system. Real life production will likely be lower, depending on conditions. 

Mistake #5 

Getting grid tie approval sounds impossible. I’m just going to add more batteries to my system and switch back to the grid only when these get low. 

The Truth:

The approval process for grid tied systems can be quite difficult (although the DOE is making it a lower priority), but the opportunity cost of purchasing batteries will be clear once you realize the upfront cost and lack of longevity. Most batteries only last a year and a half if they are routinely discharged to 50% or below. On the other hand, batteries that are connected to a hybrid inverter that keeps them float charged all the time while feeding excess power back to the grid can last upwards of 20 years. 

Mistake #6 

It’s sunny from 8 a.m. to 6 p.m. here, so my I can expect the panels to run at full power for about 10 hours a day. 

The Truth:

Most systems really see full power for only a few hours a day. The rest of the time the sun is at an angle, preventing the panels from getting the full power. Thus 10 hours of daylight might give you only 4 hours of equivalent direct sun – and direct sun is what you have to base your total energy output on. 

Hopefully this will help future installers avoid the mistakes and misconceptions of many before them. Of course, with the proper solar training these mistakes can be remedied before you leave the classroom. In any case, it is a good idea to go out with an experienced installer for the first several installations to really cement your knowledge and skills.

Energy efficient solar home

When Neil Thompson constructed his energy-efficient home in Fishers, he knew he was making an earth-friendly decision. What he didn't know, however, was how much "green" he would add to his wallet. "I'm saving roughly $1,100 a year," said Thompson, who works in power maintenance and whose hobby is installing solar units. Thompson's residence in Forest Ridge Estates will be open for free public tours this  weekend as part of the American Solar Energy Society's National Solar Tour. 

The custom home, which was built in 1985, has a passive solar design and uses a solar photovoltaic system to provide it with electricity. Thompson will be on hand to explain how the solar PV system works and talk about the costs and incentives involved with a solar installation. Homeowners like Thompson receive  additional incentives for solar installations -- including a 30 percent federal tax credit.

"A payback on a solar home is way beyond anyone's expectations," said Thompson, who said he added solar roof panels and a two-story sun room to his home."I'm amazed about the sun's influence on the home in the middle of winter. It really brightens the house." The Thompson home is not the only metro-area stop on the National Solar Tour. From 1 to 4 p.m. today, the nature center at Cool Creek Park in Carmel will hold a program to show how solar thermal, geothermal and solar photovoltaic systems work.

Advanced single-junction, tandem-junction and triple-junction PV cells

Altatech, a subsidiary of Soitec, announced today that it has introduced a multi-chamber chemical vapor deposition (CVD) system that enables photovoltaic (PV) cell manufacturers to develop and optimize their solar cell designs using advanced thin-film deposition of amorphous silicon and other materials. By performing all deposition processes within a single system, the new AltaCVD Solarlab™ tool reduces cycle times and materials consumption in fabricating advanced single-junction, tandem-junction and triple-junction PV cells.

Using the AltaCVD Solarlab, customers can deposit transparent conducting oxide (TCO) films that deliver the superior optical characteristics, high doping mobility and smooth, defect-free surfaces needed to optimize efficiency of their solar cells. 

"Extending our core CVD technology for use in solar cell development presents an additional market opportunity for us," said Jean-Luc Delcarri, general manager of Soitec's Altatech subsidiary. "Reducing the amount of material used in cells and improving photovoltaic conversion performance will be the keys to growth in the next few years. We look forward to continuing to apply our deposition expertise in both Research and Development and commercial applications for the renewable-energy industry."

In creating its newest CVD system, Soitec's Altatech subsidiary leveraged its patented chamber architecture and deposition technology, which enables the use of new precursor gases to achieve extremely high film uniformity and tightly controlled stoichiometry. These capabilities have been production-proven on the company's AltaCVD platform, which has been used in both engineering and volume manufacturing of advanced semiconductor devices since 2008.

The AltaCVD Solarlab system has the versatility to perform standard thermal CVD processing as well as plasma-enhanced CVD and atomic-layer deposition. These processes can be run over a wide spectrum of temperatures, from 100° C to 800° C, to create photosensitive films that can maximize the efficiency of PV cells in converting sunlight to electricity. In addition, the system can handle a variety of substrates, including transparent glass and both round or square silicon wafers with thicknesses ranging from 150 microns to several centimeters.

Soitec plans to begin shipping AltaCVD Solarlab systems to customers by the end of this year.

Read more here: http://www.sacbee.com/2012/10/01/4870913/altatech-launches-new-cvd-system.html#storylink=cpy

Arctic sea ice shrinks to lowest ever level

As global warming intensifies, sea ice in the Arctic has shrunk to its smallest surface area since record-keeping began, US scientists have warned. The National Snow and Ice Data Center (NSIDC) on Wednesday said satellite images showed the ice cap has melted to 3.4 million square kilometres as of September 16, the predicted lowest point for the year. That is the smallest Arctic ice cover since record-keeping began in 1979.

"We are now in uncharted territory," NSIDC director Mark Serreze said in a statement. "While we've long known that as the planet warms up, changes would be seen first and be most pronounced in the Arctic, few of us were prepared for how rapidly the changes would actually occur."

Arctic Sea ice expands and contracts seasonally, with the lowest extent usually occurring in September. This year's minimum followed a season already full of records for shrinking ice, with the lowest ever extents recorded on August 26 and again on September 4.

Liquid Solar Cells - Solar Ink

Scientists at the University of Southern California have developed new solar cells in the form of a liquid that can be painted or printed onto clear surfaces. The new technology is cheap to produce and relies on stable solar nanocrystals that are only four nanometers in size, which is so small you could fit 250 billion on the head of a pin. These particles are then suspended in liquid like pigment and can be printed like ink.

The liquid solar cell technology can be implemented under a low-temperature process, which means that it can be printed on plastic instead of glass without concern of the plastic melting. This would allow for cheap, flexible solar panels and more options in applying the solar technology.

Although the new liquid solar nanocrystals are cheaper than traditional single-crystal silicon wafer solar cells to produce, they are also much less efficient. In order to keep the particles stable, organic ligand molecules are used to attach to the nanocrystals to keep them from clumping, but in effect, also insulates them and reduces their conductivity.

Additionally, the current nanocrystals used are made of the semiconductor cadmium selenide, which is considered toxic and is restricted in commercial applications. The researchers are still working on alternative materials for the nanocrystals. Hence, it will still be a few years before we see this technology in commercial use.

Solar Electricity Basics

As a PV designer and installer, you should be perfectly familiar with the following basic electricity concepts:
 
Current is the flow of electrons through a conductor (wire). The SI unit of current is ampere (A).

Ampere represents a flow or rate of electrons movement.

The base unit of ampere is coulombs per second.

In Direct Current (DC) electrons flow in one direction.

In Alternating Current (AC) electrons flow in a back-and-forth pattern.

AC differs from DC mainly in the sense that the current/voltage alternates in flow at a specific interval of time.

Load is simply any piece of electrical equipment.

Ammeter are used to measure electrical current (AC and DC both). Two commonly used types of hand-held ammeters are:

• Inline Ammeter requires current to flow through the meter in order to be measured.
• Clamp Ammeter have a jaw on the top that opens when you press a lever on the side of the meter. To measure current you have to place conductor inside the jaw.

Voltage is an electrical pressure that encourages electrons to flow in the conductor.

Nominal Voltage is a number that represents a baseline for measuring voltage.

Operating Voltage is the output voltage.

SI units of voltage is Volt (V).

To measure voltage you can use Digital Multimeter (DMM) which is a third type of hand-held measuring device.

Resistance is the opposition of flow of DC current.

Impedance is the opposition of flow of AC current.

SI unit of resistance/impedance is ohms. 

Ohm's Law can be stated as:

 Voltage = Current x Resistance

Power is the measurement of flow of energy. It is a rate and an instantaneous value.

SI unit of power is Watts (W).

One watt is equal to one joule of energy per second. 

1000 Watts = 1 kilowatt (kW).

Energy is the measurement of power multiplied by time.

It is measured in kilowatt-hours (kWh). (It is not SI unit.)

kWh is the number on the basis of that your utility provider charges electricity bill. 

Energy in (kWh) = Power in (kW) x Number of hours (h)

Ampere Hour (Ah) is the unit of electric charge. Ah is commonly used for batteries.

Charge in (Ah) = Current in (A) x Number of hours (h)

1Ah = A x 3600s = C/s x 3600s = 3600C

A collection of 6.24x10e18 electrons has a charge of 1C (one coulomb).

Ampere-hours (Ah) = Watt-hours (Wh) / Voltage (V)

Series connections are made by connecting the positive wire from one module to the negative wire of the next module. In series connection, the voltage values are additive and current values remain the same.

Parallel connections are made by connecting the positive wire from one module to the positive wire from next module and the negative wires are connected together. In parallel connections, the current values are additive and the voltage values remain the same.

Combination of series and parallel connections can be made to obtain the desired value of voltage and current.

Solar Kids and Sun

 

• Life on earth would not exist without the sun.
• The sun is the nearest star.
• The sun's heat creates all of the weather on earth.
• Energy from the sun is free.

First Solar Power Plant Commissioned in the Provence-Alpes-Côte d’Azur France

On August 21 in the commune of Valderoure, the French subsidiary of the global market leader in photovoltaic system integration, BELECTRIC, officially inaugurated the region's first ground-mounted solar power plant. In the presence of the mayor and several regional politicians, BELECTRIC employees – who were involved in the design and implementation of the power plant – gave the guests a guided tour of the solar power plant as well as information about the performance of the plant and general information on BELECTRIC as a company. The solar power plant with an installed output of 1.86 MWp was erected on an area covering 5.5 ha and is a prime example of the Franco-German cooperation. The 24,000 First Solar modules installed generate an annual power production of approximately 2.8 million kWh, which corresponds to the average annual power consumption of around 600 households, saving the environment almost 2,500 tons of CO₂ per year.

The integration of the solar power plant in the landscape was given top priority. A standing committee with representatives from all the responsible environmental agencies accompanied the project in every construction phase. The open and honest cooperation proved successful in particular during the preparation of the site, which is a sensitive phase in terms of flora and fauna. The positive cooperation will also be an advantage in terms of the educational nature trail that is still to be constructed.  Jochen Meyer, Managing Director of BELECTRIC France, summarized his enthusiasm in one sentence: "This project is an excellent example of the positive cooperation between BELECTRIC's excellent technical, personal, and financial competences and the pronounced desire of the local representatives of the commune to set up an environmentally friendly and sustainable power supply in this region."

Solar energy replaces nuclear energy in Germany

Sun! A star located some 150 million kilometers away is unarguably the most important element for human race as it is their source of life among other vital things. In a latest breakthrough in solar technology, Germany has set an example that cannot be challenged. In late May this year, Germany solar power plants generated a record breaking 22 gigawatts of electricity per hour. This amount of electricity is equal to the power generated by 20 nuclear power plants working at maximum capacity. The 22 gigawatts produced from Germany’s solar plants was utilized throughout the country during midday hours for two consecutive days.

Last year, an unfortunate event that took place in Fukushima, where a great loss of life occurred because of the Nuclear Plant meltdown following the Japan earthquake and Tsunami in March, last year.

After the Fukushima disaster, the German government abandoned their plans to use nuclear power and shut down eight of their 17 nuclear plants immediately and plans to shut down the remaining nine by the year 2022. This move had naturally motivated the German government to look for more practical and renewable energy sources like wind turbines, solar and bio-mass which is basically biological material from living or recently living material which is turned into bio-fuel for energy.

Germany’s director of Institute of the Renewable Energy Industry (IWR), Norbert Allnoch, said that the 22 gigawatts of solar power per hour met almost 50% of the country’s mid-day electricity demands.

“Never before anywhere has a country produced as much photovoltaic electricity,” Allnoch told Reuters. “Germany came close to the 20 gigawatt (GW) mark a few times in recent weeks. But this was the first time we made it over.” he said, while speaking to Reuters. This breakthrough which was supported and funded by the German administration has proved that a full-fledged industrial country was able to keep up with a third of the nation’s energy demand on a working day and half on the weekend, when factories and mills were closed. Germany is now second in the list of countries using renewable energy sources and the leading country in the list of countries using solar technology, followed by Spain which stands at number two.

The solar power generation capacity of Germany is almost equal to the rest of the world combined. It gets about four percent of its overall annual electricity from the sun and it aims to cut its greenhouse gas emissions by 40 percent by the year 2020.

Malta Solar Plans - 2020

Resources Minister George Pullicino today awarded Alberta Photovoltaic Consortium with a letter of intent to install 67,000 square meters, or the area of 15 football pitches, of photovoltaic systems on the rooftops of government buildings in Malta.

“This company won the tendering process after 15 companies expressed interest. This investment will amount to around €20 million and will help Malta towards its 10% target of 2020,” Pullicino said.

The letter of intent was awarded on the eve of the International Renewable Energy Agency (IRENA) conference to be hosted by the Ministry for Resources and Rural Affairs in Malta.

“The conference will see ministers travelling to Malta to discuss renewable energy and islands during this global summit including the Maldives, Seychelles, Jamaica, Samoa and more,” Pullicino said.

The government identified a number of public buildings as sites for solar energy installations by Alberta on behalf of the resources ministry.

“These buildings do not just include ministries and schools, but also the roofs of reservoirs such as four in Ta’ Cenc and three in Ta’ Qali,” the minister explained.  

This project is aimed at producing renewable energy as Malta struggles to reach its target set by the EU renewable energy directive.

Malta's current renewable energy production is still at 0.4% of its gross final energy consumption, ten years ahead of its 2020 target to produce 10% of energy through alternative energy sources.

Until now, Malta is the only member state among the EU27 that still depends totally on fossil fuels to produce all its electricity needs.

Pullicino said that unlike other larger countries, Malta does not have the “luxury” of excessive space where solar or wind farms can be constructed.

“We have to take advantage of what little space we have because apart from the already developed areas, Malta has space which is of agricultural value, aesthetic value and historical value which needs to be conserved,” Pullicino said.

The 2009 Directive on renewable energy set individual targets for all Member States, such that the EU will reach a 20% share of total energy consumption from renewable sources by 2020. These targets take into account the Member States' different starting points, renewable energy potential and economic performance.

Recently, the European Commission sent a reasoned opinion to Malta and three other member states, for not complying with their legal obligation to inform Brussels of their transposition of the Renewable Energy directive.

Increasing the share of renewable energy to 20% in the EU energy consumption by 2020 relies on the commitment of member states to fully implement the requirements of EU legislation.

To reach these targets, member states have to lay down rules, for example for improving the grid access for electricity from renewable energy sources, the administrative and planning procedures, information and training of installers.

Malta’s dependence on oil will be partly reduced by connecting Malta to the European energy grid through an interconnector. A 200-megawatt interconnector will link Malta to Sicily and is set to be operational by 2013.

As for wind energy, the government's original plan presented in 2006 was to exclude near-shore and land-based wind farms in favor of a wind farm located in deep waters for which an international call for expression of interest was issued. But the technology for this kind of development was still at an experimental stage at the time.

After the 2008 election the government changed its policy by opting for a near shore wind farm at Sikka l-Bajda and two smaller land based farms in Hal Far and Bahrija. However, the efficiency and environmental impact of the wind farms are still being assessed.