Usually large scale (MW range) solar power plants are based on ground mounted installations. Solar panels here are supported on structures that are attached to the ground. Land is specifically allotted for these. Electricity generated from these is then to be transmitted (usually over long distances) to the final point of application.
Rooftop PV installations make use of the roof area available on a residential, commercial or any other building. Here the panels are mounted on support structures fastened to the rooftop. Electricity generated from the solar plants are used to power the appliances in the buildings. Usually only a small percentage of energy consumption is met through these due to space constraints.
Identifying a suitable parcel of land which is near to the local substation, has an even terrain, has adequate sunshine availability, etc. is the basic step to a ground-mounted solar power plant.
Step 2: Get a PPA(Power Purchase Agreement)
PPA is an agreement between the solar power plant owner (developer) and an off-taker (this could be a private party or the government) to buy the power generated by the developer at pre-determined rates. Study the tenders being floated by various parties and win bids issued by a suitable off-taker
Step 6: Commissioning of the plant
RCommissioning of the plant is the final step regarding a MW Solar Power Plant. Here, the developer gets government officials to certify that his plant is structurally and electrically safe to generate power to the grid.
Step 3: Get financial closure for the project
Solar projects are typically funded through Debt: Equity mixes. Loans are granted based on your financial strength and the financial soundness of the solar power project. Study the offerings from different funding organizations (including government bodies) and choose the most beneficial one.
Step 5: Due-diligence on the design and construction of the plant
Though it is the chosen EPC’s duty to implement the power plant, it is always advisable for the developer to oversee (or get professionals to oversee) the components used, the design and the actual erection of the power plant.
Step 4: EPC Selection for the solar power plant
EPCs put together the entire power plant, right from designing the plant to its construction. Choosing the right EPC could be one of the most critical decision regarding your power plant. Make sure you choose your EPC with care.
Ownership of area to put up the plant is the most basic requirement. A 1 kW system normally requires around 100 square feet of area.
2. Unshaded area
Solar plants are composed of panels wired together. Shadows can cause entire generation to be significantly reduced. To prevent this, solar panels need to be put up in areas free of shadows cast by nearby trees, buildings or other structures.
3. Roof type and orientation
Most installations are done on metal and concrete roofs. Installers maybe willing to work with other types of roof also, but this could be more complex. Age and weight bearing capacity of the roof will also determine its suitability. Also, south facing rooftops in the northern hemisphere and north facing rooftops in the southern hemisphere are considered ideal for solar plants.
Solar power plants without batteries cost a lot less than solar power plants with batteries.
2. Depends on quality of components and installer
High quality solar panels, inverters and cables, and a high quality installer could cost 10-20% more than average quality ones. Note however that a high quality solar power plant can generate up to 30% more power than an average quality plant.
3. Depends on use of trackers
Trackers generate more power from solar panels, but they can also increase the cost of a solar power plant by 10-15%.
4. Indicative costs for rooftop solar without batteries (per kW,2016)
North America- $3000
5. Indicative costs for rooftop solar with batteries (per kW,2016)
North America- $4500
6. Indicative costs for ground mounted solar without trackers (per kW,2016)
North America- $2200
7. Indicative costs for ground mounted solar with single-axis trackers (per kW,2016)
1. Ownership of land gives no additional advantage
Solar power plants require heavy investments. Land costs are only a fraction of the total investments required. Thus, owning large parcels of land alone will not give you any specific advantage.
2. Feasibility depends on business model planned
Ownership of land is nowhere as critical as having a sound business model planned, with a healthy power purchase agreement with an off-taker. Economic feasibility depends on these factors and the overall performance of your power plant.
3. Suitability of land needs to be verified
It is merely not enough that you have lots of land. The suitability of the land in terms of sunshine it receives annually, the nearness to an evacuation facility, the land profile, etc., are equally important.
Cleaning panels to remove dust and debris accumulated over time is a must. The frequency of cleaning required depends on rainfall availability in your region. If rainfall is sparse, you may need to get the panels cleaned as often as once in two weeks.
2. Maintenance of inverters
Make sure the inverters are not accumulated with dust and dirt. Qualified maintenance personnel are usually employed to monitor the inverter performance and to ensure that things are fine.
3. Maintenance of the rest of the system
Visual inspection of cables, combiner boxes, batteries, fuses for cracks, deterioration and other defects can be done by the solar plant owner once a week. Again, it is best to leave the actual activities to a maintenance team who monitor the system on a periodic basis.
A panel consists of a number of solar cells that converts sunlight into electricity. It is the main component of the plant and accounts for around 50-60% of the capital costs. Its selection has a significant effect on the overall generation of the plant.
Inverters convert the electricity from solar panels (which is in DC form) to AC form as required for appliances (end-use). Apart from this, command and control signals for electricity production from panels are provided by these.
3. Mounting Structures
Mounting structures support solar panels on the ground or on the rooftop. They provide a secure fastening of the panels and protects them against wind, water logging and other weather and external impacts.
Cables transfer electricity from the panels. Solar cables are expected to withstand long-term exposure to sunlight and other atmospheric conditions.
5. Monitoring Systems
Monitoring systems comprise hardware and software solutions that help in analyzing the performance of the power plant. They help in quick detection and analysis of faults at a component level and also provide easily accessible real-time data of the plant for maintenance.
Batteries are used to store the excess energy produced by solar panels during the day and are used to power appliances during night. Battery capacities will determine the extent to which you can depend on solar plants when the sun is not shining.
Components like combiner boxes, fuses, switches, meters, distribution boards, etc., complete the solar power plant infrastructure.
1. For ground mounted power plants without trackers
The total area required for a 1 MW ground mounted plant using crystalline panels is about 5 acres. If panels are based on thin-film technology, the area required could be 30% higher.
2. For ground mounted power plants with trackers
Employing trackers for the ground mounted plant will require 20% more area. This is to account for the difference in solar plant layout with trackers. A 1 MW solar plant with crystalline solar panels would approximately need 6 acres of land, and one with thin film panels will require about 7.5 acres.
3. For rooftop solar power plant
A 1 kW rooftop solar plant will require about 10 sq. m. of shade-free area, equivalent to about 100 sq. ft.
The extent of solar power generation depends on the solar radiation at that location, measured as DNI (direct normal irradiance). DNIs vary from 5.5 kWh/m2/day for high sunshine regions to as less than 3 kWh/m2/day for many regions with low-moderate sunlight.
2. Depends on the quality of your components
Always go for quality panels, inverters and cables. A good quality solar power system could cost 10% higher, but could generate up to 30% more than an average system, all aspects considered, over a 25 year life time.
3. Depends on maintenance
How frequently you clean your panels and monitor your inverter and other components for repairs can significantly affect generation. For instance, a poorly maintained system can generate up to 25% less power than a well maintained one.
4. Output for high radiation regions
Very high solar radiation regions can generate up to 5 kWh /kW/day on average, or about 1800 kWh per year.
5. Output for moderate radiation regions
Moderate solar radiation regions can generate in the range 3.5-4 kWh /kW/day on average, or about 1250-1450 kWh per year.
6. Output for low radiation regions
Regions with low solar radiation could have generations as low as 2.5 kWh/kW/day on average, or just 900 kWh/year from 1 kW. Solar power might not be recommended for regions with solar power generation lower than 900 kWh/year/kW.
Sloped land, excessively rocky terrain, uneven land, etc. may make a site non-viable for solar plant installations. Such sites will significantly add to total investment required in terms of workmanship and technology, making them not very attractive.
2. Power evacuation facility
Generated power from the plant needs to be transmitted through the nearest substation. For this, the substation must have adequate capacity to evacuate the power generated from the site. Moreover, nearness to existing distribution lines (ideally should be within 1-2 k.m.) is equally important for transmission of power from site.
3. Local weather conditions
Sites with low sunshine availability, susceptible to floods, sandstorms, etc. are usually considered non-ideal for solar power plant installations.
4. Proximity to roads
Proximity of a solar plant to a main road can offer an economic advantage as the transportation costs affect the overall cost benefits.
1. Grid-tied systems do not work if there’s no grid power
Most rooftop plants are connected to the utility grid with no backup power source. Under this configuration, if the grid fails, no power is generated by the solar power plant even when there is sun.
2. Using batteries increase costs
Solar power generation is restricted to day-time (while sun shines). You need batteries to store the solar energy in order to power appliances during nights. Batteries are expensive and can significantly increase the overall cost of solar power.
3. Rooftop solar might not contribute enough for your power consumption
For industrial and commercial enterprises with a high energy consumption pattern, rooftop solar power plants are most likely to contribute only a fraction of their total energy requirements (usually around 10 – 30%) owing to limited rooftop areas.
4. Solar cannot provide 24x7 power
Solar plants depend on sunshine for power production. They hence do not produce power during night time or non-sunny days unless large battery capacities are used - an expensive proposition.
5. Significant land area required
A 1 kW solar plant requires around 100 square feet of shade free area. Large solar plants consequently require significant area.
Solar plants depends on sunshine for power production. Solar generation cycle is usually from 7:00 a.m. to 6:00 p.m. During night time, solar plants without batteries do not generate power.
2. With batteries, yes, but could be expensive
Batteries store solar energy to be used during a non-sunny day or nights. Using batteries can increase the cost of solar power by 50% or even higher, depending on the amount of battery used.
3. Only limited contribution
For large companies and industries, rooftop solar can usually satisfy only a minor portion of their consumption. Limited rooftop area and solar generation limited to day-time are the major reasons for this.
4. Net Metering act as a virtual battery
Net-metering is a mechanism through which you can export the surplus power generated by your rooftop solar power plant to the grid. This export gets accounted for in your bills, and thus the surplus power generated by you is not wasted.
Business models are available through which you can have a rooftop solar power plant with no upfront investment. In such a case, a third-party puts up the solar plants on your rooftop and you are expected to pay a fixed price per unit (usually lesser than the grid rates) for the electricity produced.
2. Limited upfront investment through loans
In most cases, solar power plant owners avail bank loans for the investment. Thus, the owner only pays up a portion of the capital costs and the rest is funded through debt to be repaid over a period of time, thus reducing upfront costs.
3. Yes, through rooftop leasing models
Under rooftop leasing models prevalent typically in the US, investors put up rooftop plants for a user who pays EMIs for the power generated. After a pre-defined payment period, ownership gets transferred to the user.
1. Benefit by supplying the surplus back to the grid
If you are eligible for a scheme called net metering , you can benefit from the excess electricity. Net-metering is a mechanism through which you can export the surplus power generated by your rooftop solar power plant to the grid. This export gets accounted for in your bills, and thus the surplus power generated by you is not wasted.
2. Store the surplus in batteries for later use
Batteries store the excess solar energy which can be used when there is no sun. However, using batteries can increase the cost of solar power by 30% or higher, depending on the storage capacities opted.