Electrical power providers are generally providing two different tariff structures, the first is called flat rate structure, in which the price for the purchased kWh is fixed, its same over 24hours/7days. And the other structure called time of use, in which the price for the purchased kWh differs from time to other, there will be off peak price and high peak price. Usually, off peak time is in the night, high peak time is from afternoon to the evening, and the normal time is represented by the rest of the day hours, in some areas, the high peak kWh charges may reach 50 cents per each kWh. Therefore, we must choose a reasonable electricity price according to our own needs.
The inverter is the heart of the solar photovoltaic system, and more than 90% of solar system failures causes is due to inverter malfunction. There are 2 main factors affecting solar inverter selecting; inverter performance and its price.
The solar panel spend its life in rains, hot sun, etc. It works outdoor and exposed to harsh environment in summer and winter. These changes in weather will of course affect the solar internal components and material bonded to each other, there will be chemical changes which will affect not only the solar panel performance, but it will affect its life time, its efficiency and reliability, because these chemical reactions will create new chemical material. Moreover, the elasticity of these internal materials will change with the time pass and affect the tension and stress forces taken place between different parts.
So, the cheap low quality solar panel which uses cheap and low quality materials, and which its manufacturer has not taken into consideration the parameters aforementioned will not withstands/survives much, provides low performance and low service life.
If your building/house is heavily shaded. As the shadow will dramatically reduce the solar system generated output electricity. In your vision you have to take care and consider about the impact of the current shadow and the anticipated shadow comes from trees grow or known renovations and extensions in surrounding buildings, that what we called shadow analysis study. It is an important study assisting us deciding whether the solar system will be a good beneficial investment project that worth to proceed or not. One more thing to note, is that in case of locations subjected to such shadow, its recommended to use micro solar inverter, so you can distribute your solar panels freely and avoid areas with heavy shadow.
What will be the expected annual generated electricity (kwh) form your solar system as a whole? And will your solar system installation company be ready to provide written statement about that. That is the strict performance indication, and if the solar company provide such statement, then be rest assured your system will be of high performance and efficiency.
The solar installation company has to agree with you before installation who will be responsible of repair and replacements costs if needed. This point should be clear and documented.
The most important step is that you have to make sure that your solar company will be in charge of installation, installing metering device, and to connect solar photovoltaic system with the grid. Solar company invoice you have to pay should have the prices of these tasks and all relevant works. However, in general, the electricity company will supply such solar energy meter and install or supervise on its installation.
After installing the solar energy meter, your solar photovoltaic system is ready to run and produce electricity.
One of substantial financial saving we can get from solar photovoltaic system is to make what we called "load shift". It means to shift electrical power usage from night times to daylight times in where the sun is shining and the solar system generates such free electricity. We strongly recommend to run your high power equipment in day light time, like dish washer, clothes washer, pool pump, dryers, water heater, electric heater, electric cars, etc. By this way you can make big financial saving and avoid paying high electricity bill to the electric utility. Also, it is worth to pay your attention to using timer to achieve smoothly operation of such equipment to daylight hours, it will be very helpful way to avoid the forgetting.
Make your solar system installer from the beginning aware that he will be responsible for making all electrical connection especially the electricity meter and getting all approvals required by your electricity retailer "power grid"and to insert costs of these works in your quote. Actually this process varies from state to another and from country to another.
You have to get a clear date to start and finish your solar system installation from the solar company.
Make sure that your solar company contacts the electricity retailer "power grid"to arrange procedures for the new electricity meter installation.
That is the common setup system, its connected to the power grid, the electricity generated from solar will be first used to run your loads "equipment/appliances", and if there will be surplus electricity generation, it will exported to the power grid, and your power retailer will pay you for it (approx. 6-30 cent per kWh), and if the solar generation is not sufficient or not operating (night), electricity will be imported automatically from your retailer and you will pay for it at the end of the month.
Generally, in hybrid system, the batteries capacity will not be large, so it’s not sufficient to run the whole system in case of grid shutdown, but it will be able to run certain appliances with dedicated “separate” circuits after disconnecting the home from the grid, so you should specify these certain appliances like important medical equipment or fridge, etc. to your solar system designer at design stage.
There are two main types of solar batteries in the market; Lead acid and lithium. Although adding such batteries to the solar system will add extra significant expenses on solar system price, but it has much benefits; It will reduce our electricity bill, and we will be independent of the grid keeping our equipment work in case of grid interruption, and this is critical high value benefit in places/areas prone to grid blackout or even has no connectivity with the grid, and specially for some kinds of sensitive equipment like fridges, freezers, and medical equipment.
The solar photovoltaic system power generation in sunny day is approx. 4-5 times the cloudy day, so we need to delay operating our big power capacity appliances, like dryer, washing machine, and dish washer in cloudy day to the next sunny day. In general, when solar generation is low then do Not run all your appliances at the same time, and delay those which can be delayed without harming your lifestyle to the next sunny day, in order to avoid purchasing electricity from your local grid and pay more for your electricity bill. So, please do your jobs in sequence rather than doing them simultaneously.
Also, for your Air conditioner, you can pre-heat or pre-cool your home at daylight time, so stored heat or cool on your home wall will provide a comfortable whether in the evening. This way can save you much money compared to the Air conditioner regular operating time from 5pm To 9pm when usually the household returned back to home.
One of the most external factors affecting solar photovoltaic performance rather than the 3 factors aforementioned, is how much solar irradiation exists in that country/location. There will be many calculators available on internet free of charge that provide us with accurate sun irradiation data for each place in the world. This calculator estimates the output power from the solar photovoltaic system based on optimal criteria, means best orientation, best pitch angel, no shadow, and standard good quality solar panels.
Do internet solar research, and speak to your friends who already installed the solar system. The goal of such searches is to discover good brands, prices in the market. Usually cheap prices correspond to lower quality, but keep in mind that your solar system should last for 25 years in order to get a good return on investment, so good quality is our first consideration.
Choose the high quality and the high efficiency solar Inverter, as the inverter is an essential and crucial part of the solar system, the motor efficient it is, the better energy conversion we get. We recommend to choose the best brand with long warranty period.
For each individual solar panel brand/manufacturer, there will be specific characteristics that will affect the whole solar photovoltaic system performance. To be more specific, we mean by the word "performance"; the output electrical power we can get from the solar system "the harvest".
Based on real testing procedures made be the solar specialists/experts, there will be approx. 10% difference in solar panel output power based on its own properties, which are represented by 3 major factors/specifications as following:
The sun releases very tiny energy packets called photons. These photons come from the sun to the earth in approx 8-9 minutes. In theory, the number/volume of photons incident on the earth per hour is enough to meet the world's energy needs for one year. Imagine how much energy we get from the sun!
Payback period refers to: In how many years our solar system will return back its fixed and running costs we should pay for. Basically, before proceeding in purchasing/installing any kind of solar system and due to their high initial costs, we need to make economical feasibility study to know how to calculate the payback period and whether this solar system will be profitable project or not.
Of course, using solar photovoltaic system will substantially reduce our electricity billsand may eliminate them totally, but we can also reduce electricity bills by reviewing our power consumption to reduce electricity usage and electrical losse. Let us introduce nine tips and approaches to achieve that:
1. Replace your bulbs whether they are incandescent or halogen to led lights, as this will achieve 75% energy consumption reduction.
2. Switch off appliances which are on standby mode and not actually used like old air conditioner which pulls large power in standby and like television & mobile charger, etc. All should be switched off when we do not use them.
The electricity consumption in homes differs based on home size, number of resides, home wall insulation, heating/cooling system presence/ capacities, number/ type of electrical appliances, and of course the life style. So, large homes with pools, and air conditioning units will exhibit high consumption with high electricity bill more than small homes, and always the home owners are looking forward to reduce the consumption/bills which is critical in large homes. In fact, there will be 2 main opportunities to reduce electricity consumptions and save your money.
When sizing the solar photovoltaic system, we should mind some logic important factors that have substantial effects on solar system itself and our electrical appliances/equipment:
1. If we don’t use the electricity generated from the solar photovoltaic system during the daylight hours instantaneously, it will be exported back to the power grid if we have grid tie solar photovoltaic system type.
Solar feed in tariff is how much will you be paid for the electricity generated from your solar photovoltaic system and send back to the power grid. Of course, the electric utility in your location which receives the power, will be on charge to pay you.
Actually solar feed in tariff value differs from one country to another, moreover, it differs from one state to another. In United States, every state has its own guidelines, and every retailer has a certain tariff. So, if you decide to install photovoltaic solar system in your facility, you will be needing to check different retailers in your location for the best price.
