Claims:We claim:
1. A system for rainwater harvesting in solar parks, the system comprising:
at least one solar panel having a gutter attached to the solar panel for collecting the rainwater, and at least one discharge opening for outflow of the collected water, wherein the gutter is designed in such a way that the collected water within the gutter flows towards the discharge opening;
a storage unit for storing the collected water;
a connecting means extending from the discharge opening of the gutter to the storage unit for allowing flow of the collected water from the gutter to the storage unit.
2. The system as claimed in claim 1, wherein the gutter is having U- shaped or V- shaped structure.

3. The system as claimed in claim 1, wherein the connecting means comprises a funnel-like structure below the discharge opening of the gutter for maintaining the required flow rate of the collected water from the gutter to the storage unit.

4. The system as claimed in claim 1, wherein at least one filtration means provided between the gutter and the storage unit for filtering the collected water, wherein the filtration means and the connecting means are designed to maintain the required flow rate of the collected water from the gutter to the storage unit.

5. The system as claimed in claim 1, wherein the storage unit can be above or below a ground.

6. A system as claimed in claim 1, wherein the solar panel comprising a gutter on at least three edges of solar table.
, Description:FIELD OF THE INVENTION
The present invention relates to a solar and/or rainwater harvesting system, in particular rain water harvesting in the solar parks.
BACKGROUND OF THE INVENTION
Precipitation is one of the crucial aspect in maintaining growth and ecological balance on the earth. However, rapid development and concretization of open spaces such as roads, grounds, public plazas, and parking areas have resulted in the large storm water run-offs that is wasted in urban drainage systems. This has led to major issues concerning usage and preservation of rain water. In addition, water scarcity is also increasing due to lack of sufficient available water resources to meet the demands of water usage.
Further, primarily electricity is generated using fossil fuel and hydrocarbon based power plants. Burning fossil fuels produces energy necessary to run homes, offices, and automobiles. In the process, they release pollutants and contribute to global warming. Two of those pollutants sulphur dioxide and nitrogen oxide react with water or moisture in the air to form nitric and sulphuric acids. These chemicals fall to the earth in the form of acid rain, damaging trees, soil, and waterways. Unfortunately, the process that provides electricity to so many homes is also a major contributor to global climate change.
Moreover, mercury that escapes coal-burning power plants through smoke stacks may wind up settling on rivers, lakes, estuaries, and bays. Fish absorb the mercury and then pass it along to humans who eat the fish and are especially harmful to the nervous systems of unborn fetuses, babies, and young children.
For these and other reasons, people have started to look at alternatives when it comes to providing electricity as well as saving rain water. However, there is no efficient mechanism to harvest solar as well as rainwater from open spaces such as roads, grounds, public plazas, parking areas.
Renewable energy has been an important component of energy planning process for quite some time, especially since it makes significant contributions towards climate change mitigation and emerge as a responsible global powerhouse. Solar energy has rapidly emerged as a reliable, affordable, and clean solution for meeting world’s fast-growing energy demand and supply power to all.
For harvesting solar energy roof top panels are installed for domestic and small scale use. Now the governments are also making efforts to use cleaner energy solutions and reduce the pollutants. That leads to mega solar parks across the world. The area covered by these solar parks is very large. As for production of 1 MW of solar energy approximately 5 acres of land is required. Accordingly, for a solar part of 20 MW capacity approximately 100 acres of land is required.
The Solar Panels Farms are generally situated in dirt and dust areas which is mostly in case of tropical countries. The performance of solar panels depends on various factors, the power generated by farm can decreased if there is dust and dirt on panels and this is the main factor for reduction. One can generally assume a reduction of about 40% - 50%, if the panels are not cleaned properly for 1-2 months. So to overcome this problem and to increase the efficiency of power production cleaning of module on regular basis is necessary.
Generally, two methods for cleaning the solar panels are in use. As one alternative Nano coatings are extensively used on glass. A coating can make glass hydrophobic and dust repellant and therefore makes it easier to clean the glass. Rain with pollution leaves a lot of dirt. Just like the cars, PV modules will need cleaning regularly and this is where the application of Nano coatings may be handy. In other known method. In other method for cleaning the solar panels robotic brush and dry air clean are used. The above described methods are proved to be expensive as compared to cleaning the panels by water spray in non-rainy season.
The cleaning of the PV modules in countries like India, where precipitation and water resources are in abundance is mostly done by spraying water in off rainy season. For cleaning the PV modules in solar parks, a separate water tanker carries water from one place to another and the water is sprayed and the dust is wiped manually. This results in lots of water wastages, which generally comes from the ground water.
Another major environmental problem these days is reducing ground water level due to excessive exploitation of the ground water. Recent droughts and concerns with water shortages have been encouraging governments to encourage rainwater collection.
The increasing need for fresh water, combined with the current energy crisis could make solar PV systems a more attractive option for their multi-faceted role in our sustainable future.
Hence, the object of the present invention is to develop and design an efficient and cost effective system to resolve one or more aforementioned issue.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a system for solar and/or rainwater harvesting in a solar park. The present invention provides a solution to two major problems facing developing countries: scarcity of drinking water and electricity.
According to an embodiment of the invention, a system for rainwater harvesting is provided. A gutter is attached to the edge of the solar table of the PV module so that when it rains, the rain water runs over the module due to inclined surface of the PV module and gets routed to the gutter.
The gutter which is attached is a U-shaped or V-shaped structure to collect water and at least one discharge opening for outflow of the collected water. A storage unit for storing the collected water; a connecting means extending from the discharge opening to the storage unit for allowing flow of the collected water from the module to the storage unit is also provided.
In another embodiment of the invention a filtration means is provided between the PV module and the storage unit for filtering the collected water.
The rainwater harvesting system is designed in such a way that the collected water flows towards the discharge opening. The connecting means and filtration means are designed to maintain a required flow rate of the collected water from the PV module to the storage unit.
According to an embodiment of the invention a gutter is provided across all the solar module tables in a solar park in an integrated way with each other to form a network of water lines to collect rain water.
In another embodiment, the present invention provides a system for solar and rainwater harvesting to be installed in open spaces, the system comprising at least one PV module for harvesting solar energy with a gutter to be installed for collecting the rainwater in the open space, the gutter having U or V-shaped structure to collect water and at least one discharge opening for outflow of the collected water; a storage unit for storing the collected water; a connecting means extending from the discharge opening to the storage unit for allowing flow of the collected water from the PV modules to the storage unit.
According to an embodiment at least one filtration means is provided between the gutter and the storage unit for filtering the collected water.
The water is stored in more than one water storage units connected by the conduits or water channels. The multiple storage units enable to collect the water at different times like first rain, and subsequent rains. The water from first rains generally used for ground water recharge and water from subsequent rains can be utilized for other purposes.
According to the present invention, the connecting means and filtration means are designed to maintain a required flow rate of the collected water from the solar panel to the storage unit.
BRIEF DESCRIPTION OF DRAWINGS
Reference will be made to embodiments of the invention, an example of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although, the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
FIG. 1 shows a PV module with U shaped gutter across the PV module according to an embodiment of the present invention.
FIG. 2 shows a system for rainwater harvesting to be installed in open spaces according to an embodiment of the present invention.
FIG. 3 shows a rain water harvesting system for solar park having multiple PV Solar modules; and
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a system for solar and/or rainwater harvesting to be installed in open spaces to store the rainwater or charge ground water level and/or to harvest solar energy.
The present invention in first embodiment provides a system for rainwater harvesting to be installed in open spaces especially in solar parks. The system comprising at least one solar panel to be installed for capturing rainwater in the open space along with the solar energy. A gutter is attached to the edge of the solar table of the PV module so that when it rains, the rain water runs over the module and gets routed to the gutter. The water harvesting system comprises at least one discharge opening for outflow of the collected water; a storage unit for storing the collected water; a connecting means extending from the discharge opening of the solar panel to the storage unit for allowing flow of the collected water from the gutter to the storage unit; and at least one filtration means provided between the gutter and the storage unit for filtering the collected water.
The surface of the solar panel is generally inclined at an angle thereby facilitating easy flow of the water falling on its upper surface, which is directed to gutter and through the discharge opening is directed to conduits.
Further, the discharge opening can be provided with a filtration means to avoid collection of larger dust and solid particles, etc.
The solar module comprises at least one solar panel and optionally a solar tracking device for orienting the solar panels based on the solar light. The solar cells are made according to specification and laminated between clear polymer sheets making it useful to clean rainwater collection. The angle of the solar panels can be adjusted to optimize solar generation such that they are all oriented at an angle according to the latitude of the location on which it is to be installed.
Moreover, as multiple solar modules are installed in large solar parks an effective and efficient harvesting of the solar energy the rain water harvesting can shall proportionally larger. The solar power generated from the solar module in the solar parks is connected to the grid or can be stored to a suitable storage device.
According to the present invention, the storage unit is used for storing the collected water from the solar parks. Further, the storage unit may be connected to other centralized storage unit for storing the collected water. Advantageously, the storage unit can be installed above or below ground, and can be used for cleaning the panels or other domestic purposes after process of cleaning etc.
The connecting means extends from the discharge opening of the solar panel to the storage unit for allowing flow of the collected water from the gutter to the storage unit. The connecting means is designed in such a way that it maintains the required flow rate of the collected water from the gutter to the storage unit.
Advantageously, the filtration device is removably adapted in the connecting means for filtering the collected water to make it partially ready for potable use. One of such filtration means is a filtration screen in the form of the cuts adapted at the discharge opening of the gutter and other is a filtration device removably provided in the connecting means. The filtration device may be used purpose in mind i.e. for removing fine dust and dirt particles in the rainwater. The inclined design of the filtration means increases the surface area available for filtration wherein the collected water enters from outside to inside for filtration, thereby providing to be more effective than a horizontal mesh or membrane and improving the flow rate of the water passing through it. The vertical filtration has an added advantage as it uses gravity instead of passing water through filter via forced method (e.g. pump), there by using no excess energy in the filtration process.
According to the present invention, an UV (Ultraviolet), Reverse Osmosis (RO) or any microbial filtration system can be connected to the storage device removably or fixedly to obtain potable drinking water.
Referring FIG. 1 shows a solar panel (100) for rainwater harvesting installed in open space according to an embodiment of the present invention. As shown in FIG. 1, the solar panel (100) comprises a gutter (110). The gutter (110) may be of different shape and sizes according to size of the solar panel. The gutter (110) may be U shaped as shown in Fig. 1a or V-shaped as shown in Fig. 1b. As the solar panels are generally inclined at an angle, the rain water which falls on the upper surface (102) of the panel slips into the gutter (110) attached to the panel (100). The gutter (110) may be provided with discharge opening in its length or the discharge opening can be on its ends.
Fig. 2 shows a set of two panels (100) with discharge opening (130). The water collected in gutter (110) is discharged to a connecting means (140) extending from a discharge opening (130) of the water harvesting system.
As shown in the FIG. 3, the solar panel (100) has a gutter (110) to collect rain water falling on the surface (102) of the panel (100) and a discharge opening (130) for outflow of the collected water. The gutter is designed in such a way that the collected water within the gutter flows towards the discharge opening (130). Advantageously, the filtration means (120) prevents larger impurities such as leaves and other dust particles from entering into the connecting means (140). The filtration means (120) can be made of materials like fabric, metal, etc.
As shown in FIGS. 2 and 3, the system optionally comprises a funnel-like structure (150) to receive the water coming from collecting means (140) to prevent wastage and maintaining a required flow rate of the collected water from the gutter (110) to the connecting means (140).
As shown, the filtration device (120) connected to the bigger conduits (160), the filtration means (120) is not described herein details, is used for removing fine dust and dirt particles in the rainwater. The vertical design of the vertical filtration means (120) increases the surface area available for filtration, wherein the collected water enters from outside to inside conduit (160) through the vertical filtration means (120), thereby providing to be more effective than a horizontal mesh or membrane and improving the flow rate of the water passing through it. The vertical filtration has an added advantage as it uses gravity instead of passing water through filter via forced method (e.g. pump), there by using no excess energy in the filtration process.
As shown in FIG. 3, the lower discharge point (180) can be connected to piping systems to allow connection to other systems or an existing storage unit (300).
The water stored in the storage unit (300) can be drawn with the help of pump (301) and after passing through it filters (304) and reverse osmosis (305) it can be supplied for drinking and other household activities.
The proposed system saves all the rainwater and solar power received on the PV modules. The theoretical calculations in estimating the amount of rain water that could possibly be collected in a 110 acres of land area (catchment area) with an average annual rainfall of 700 mm resulted to be around 192 Million Litres. The calculations are worked out by considering Vedasandur Solar PV Farm, India, the below table gives a brief outline of the theoretical study being conducted,
Details Values Units Data Source
Land area for lMWp 5 acres
Installed capacity in Vedasandur 22 MWAC
Total Land area in Vedasandur 110 acres
As per Water Conservation Division, Austin The volume of water collected from 1000 sq. for every rain fall of 1 inch 550 Gallons Water Conservation Division, Austin
1 Gallons equivalent to litres 3.79
Total land area of Vedasandur site in sq. 4,791,600 sq.
Average annual rainfall in Vedasandur region 700 mm/year Ministry of Water resources, Central Ground Water Board February 2008
Theoretical volume of water possible to be harvested 72,628,622 gallons
Volume in Litres 274,929,120 litres
Volume in million litres 274 Million Litres
Excluding: 5% in Land calc + 5% Collection loss +10 % uncertainty+ 10% other losses 192 Million Litres

The yearly internal water consumption for module cleaning, drinking water & other water consumption for Vedasandur Solar PV Plant, India is worked out by considering the following assumptions,
• Litres of water required for cleaning a Solar PV module (1.9 x 0.9 m)
• 24 cycles of Solar PV module cleaning cycles per year.
• 30% of volume of water calculated above is considered for other purposes.
• The following table briefs the calculations,

Details Values Units Data Source
Installed DC Capacity 26.1 MWp
Approximate # of modules 81570 Wp
Approximate water for cleaning 5 litres/module/cycle General Industrial considerations
Volume of water consumption/cycle 407850 litres/cycle
# of Module Cleaning Cycles/year 24 Cycles/year
Drinking & Other Water consumptions 3 Million litres
Volume of water consumption/year 13 Million litres

Therefore, this requirement for the consumption of the water at solar plants and parks can be easily met with rain water harvesting and also surplus water can be collected which can be used for ground water recharge or domestic purpose.
While the present invention has been described herein with respect to the various exemplary embodiments, it will be apparent to one of the ordinary skill in the art that many modifications, improvements and sub combinations of the various embodiments, adaptations and variations can be made to the invention without departing from the scope thereof as claimed in the following claims.