Solar Hybrid Power Systems and India 16

Why Opt for Hybrid Solar Power

Solar/wind/biomass all have some or the other drawbacks, such as solar panels are costly & is not available in night or cloudy days; wind turbines can’t operate in high or low wind speeds and biomass plant collapse at low temperatures. So if attempt is made to develop a hybrid solar power system combining all 3 power generating system; drawbacks of each can be balanced out.

It is known that in northern hemisphere on windy days solar power is limited and vice versa and in summer/rainy days biomass plant can operate in full power. The cost of solar panel can be subsided by using glass lens, mirror in order to heat up fluids that rotate the turbine that is used in both wind and biomass power generation systems. During winter nights or cloudy winter days when there is very low wind speed; hydrogen can be used as a fillip. Hydrogen can be stored; is a good fuel and burns with oxygen to give water. Hydrogen can also be used to maintain temperature of biomass plant in winter so that it can generate biogas for power generation. Biomass that works at its peak in summer when solar power is also at its peak can complement each other. The excess energy produced can be used in production of hydrogen that can be stored in batteries.

As such hybrid renewable energy systems have gained traction as stand-alone power systems to provide assured power supply in remote locations; use of solar power alongside other renewable resources is set to grow further. Advances in renewable energy technology; and the steady rise in oil prices has prompted the use of hybrid energy system as a best alternative. Solar hybrid power usually consists of solar and one/two or more renewable energy sources working alongside to provide consistent power with a drop in performance.

The most common type of hybrid solar power system combines the use of photovoltaics (PV) and diesel generator; where diesel generator are used as gap filler between present load and actual power generated by solar PV system. As solar energy fluctuates, and diesel generators capacity is beset with its limit, storage of power in battery is an option that can help enhance solar power contribution. The hybrid solar power system are normally found in remote locations that are off grid and transporting diesel to run the generators over long distances can be costly affair.

However as the diesel generator is a prime reason for smoke and noise pollution; use of solar-wind combo as a solar hybrid system is gaining importance. The combination of wind turbine and solar complement each other as not only both are non polluting renewable resource but both can be used as each others back up at different times of the day and year; such as during winter the wind turbine works at peak output while solar PV system works at peak during summer. A hybrid solar power system combines the best of grid-connected and off-grid solar power system. As off-grid hybrid solar it includes utility backup power, or in case of grid-connected hybrid solar it works with extra battery storage.

Hybrid Solar Power System

Hybrid solar power systems are a combination of energy storage with grid connected solar power system, providing the much needed flexibility to store energy generated in the day using batteries at night, instead of feeding it back into the grid at low prices and buying back power at higher prices. A sophisticated hybrid solar power system can provide a strategic advantage in terms of reliability, costing, environmental impact of electricity usage over traditional power sources like coal or a single renewable power source like only solar or only wind or only biomass.

It can be said that traditional grid connected solar power systems can only operate during the day and cannot work during a blackout. While solar power production peaks during the daytime, energy consumption is maximum during morning and evening time. As such using a hybrid solar power system is the best option for a household that opts for a solar power system.

A hybrid solar power system work even when the grid fails. The hybrid systems can disconnect from the network in case there is grid interruption when a standard solar system shuts down. Users can continue to run certain appliances using storage battery.

2. Outsmart the Utilities

A hybrid solar power system can do ‘load shift’. It means that the energy generated in the day is not fed back into the grid but is stored for use in the evening or whenever needed. This also enables battery systems to operate as a backup power supply (UPS) during blackouts.

Advantage of Hybrid Solar Power Systems

• If power generated by solar panels is insufficient to meet daytime requirements as well as charge the storage batteries, the hybrid solar system can recharge the batteries from the grid if and when a lower off-peak power rate is available.
• When the power usage goes beyond certain limit, utilities may put higher charges. Hybrid solar power systems can provide ‘peak lopping’ wherein stored battery power can be used to balance power usage.
•  Grid support can also be provided by hybrid solar system if grid connection isn’t capable of supplying the required load. The hybrid system supplies the extra power thereby avoiding a costly upgrade of a property.
• Hybrid solar systems are less expensive to maintain than regular off-grid solar systems. A backup generator isn’t needed, and storage battery numbers can be reduced as per requirement.
• Hybrid solar power systems have resulted in many innovations such as new generation inverters that allow homeowners to take advantage of change in electricity rates in a day.

Solar panels generate maximum output around noon the time when price of electricity peaks. Hybrid solar power systems can be programmed to consume power during off-peak hours.

Why Store the Solar Energy in Battery?

As many governments and utilities cut down on the solar feed-in tariff; ie the money or credit received in lieu of feeding excess solar energy produced into the electricity grid; it means grid-feed systems have or slated to become less economical. The prime reason is that people mostly work during day time when the solar power system works; and are not home to make full use of solar energy. As such the energy generated being excess is fed back into the grid. However, in case of commercial establishments that mostly operate in the day time; the grid-feed solar power system is the most economical option.

As such storing the power generated using solar panels is the best option for homeowners. Hybrid solar battery systems store the energy generated in a battery for use in the evening. As the cost and usage of electricity is at its peak in the evening; a hybrid solar battery storage system can help cut electricity costs. Hybrid solar battery systems works the same way as an off-grid power system but the battery capacity needed is far less.

Advantages of Solar Hybrid Battery System

• Helps reduce power consumption.
• Allows use of solar power during peak times.
• Stores & saves solar power during off-peak time.
• Allows advanced energy management like peak shaving/load shifting.
• Power is available even during power outage via UPS.
• Enables energy independence for homeowners.

 Disadvantages of Solar Hybrid Battery System

• Higher cost of batteries means the system costs more than grid-feed solar power system.
• Battery life of 7-15 years but excess use shortens battery life.
• A more complex installation needs more room and higher install cost.
• Restrict number of appliances that can used at the same time depending on system capacity.

Key Points to Consider to Purchase a Battery Storage System

There are several points that need to be considered while purchasing a battery storage system for use with hybrid solar power system. While important ones include brand, serviceability, cost, weight; other issues/points to consider are also important. These are:-

• Does the system provide electricity to your home if electricity grid fails? It’s not so important in suburban areas where power outages are not common but can be important issue in semi urban/rural areas.
• How much power will the system provide after the depth of discharge has been taken into account.
• How many cycles will the battery last for and how long is the warranty.

Hybrid Solar Power UPS / Inverters

Hybrid solar power inverters are essential for a hybrid solar power system to work to its maximum potential. These are available in 2 different broad categories; one is basic all-in-one hybrid inverters and the other is advanced grid interactive inverter systems (or off-grid).

1. All-In-One Hybrid Inverter/UPS System

The all-in-one Hybrid UPS/inverter is the most economical hybrid solar Inverter. It contains a solar inverter and battery inverter/charger and controls that can be programmed to efficiently use the stored solar energy. Its’ basically a hybrid inverter coupled with a lithium battery. These are available in 3 main categories.

1.1   All-In-One Inverter (No Back-Up)

The All-In-One Inverter/UPS (No Back-Up) is the most basic hybrid solar inverter and works like a grid feed solar inverter but also stores solar energy in battery. It cannot supply power if there is a blackout. If grid stability isnt issue then these hybrid inverters’ are the best choice.

1.2   All-In-One Hybrid Inverter with Back-Up

The All-In-One Hybrid Inverter with back up/UPS is far more efficient and advanced than the all-in-one hybrid inverters. These inverters can be used as both as on-grid or off-grid inverters based on their back-up capacity. Under normal circumstances it supplies power to the home, charges batteries and feeds excess power into the grid. In case of a blackout/power interruption it automatically switches over to battery supply and continues to operate independently from the electricity grid.

1.3   All-In-One Hybrid Inverter with Integrated Battery

The all-in-one hybrid inverter with integrated battery system is one complete unit and is the most cost effective option. These inverters are very easy to install and virtually work as standalone systems.

2. Grid Interactive Hybrid Solar Inverter

Until recently most hybrid solar power inverters were made up two different types of inverters that worked together as an AC coupled system; a solar inverter and a battery inverter. The Grid Interactive Hybrid Solar Inverter acts as battery inverter/charger and complete energy management system. These inverters supply power in same fashion as off-grid inverter but can control grid connection ie; import and export of power and can be used to auto start a back-up gen-set (generator). The grid interactive system feature include:-

• Powerful battery inverter to supply and handle continuous high power loads.
• High pass through power capability.
• Advanced multi-stage charger for lead-acid or lithium batteries.
• Automatic AC transfer switching (UPS function) built-in.
• Generator control – auto start / stop capability.
• Peak shaving possible to help cut peak demand.
• Used for high end off-grid power system.
• Remote monitoring possible.
• Grid feed-in and limiting capability when excess power generated.
• Load shifting and advanced energy demand management.

The advanced interactive UPS/Inverter systems can be used for off-grid and hybrid installations. The built in software runs these Interactive inverters managing situations like peak shaving, as well as data logging and PLC capabilities through digital input/outputs and relay control. These inverters can also work backed by battery banks and even monitor the battery performance using temperature sensors that can help prolong the life of batteries.

Equipment Used in Hybrid Solar Power Systems

A typical hybrid solar power system includes the many additional components such as:-

Hybrid Solar Power in India

Hybrid Solar Power in India

In india the hybrid solar power scenario hasn’t created that much interest as to what solar, wind, hydel, biomass, biogass have created individually. Canals carrying water have been used to set up solar PV systems in Gujarat but these are not ideally hybrid as the water is mainly used in irrigation. Despite this small steps are being taken to popularize hybrid solar power in India. Solar wind hybrid power is the most accepted and deployed hybrid solar project in India. In India, the first-of-its-kind solar wind hybrid power pilot project was started in one of the villages at Morni hills, Haryana in 2008. After that more and more villages that are far off the grid but enjoy abundance of solar and wind throughout the year are opting for such similar system. Haryana Renewable Energy Development Agency (HAREDA) after completion of the first project has deployed similar projects in Aravalli belt of Haryana.

Solar-Wind Hybrid Power

The hybrid solar wind turbine uses solar panels to convert sunlight into energy and wind turbines use wind to generate energy. A solar wind composite power inverter contains the needed AC to DC transformer that helps supply charge to the installed batteries from AC generators. Based on the need the power generated from the solar panels and wind turbine is filtered and stored in the battery bank.

The solar-wind hybrid system records the lowest unit cost value to maintain the same level of (Deficiency of Power Supply Probability) DPSP as compared to individual solar and wind power systems. For all loads; the level of energy cost for solar-wind hybrid power system is lower than standalone solar or wind energy system. As such it is expected that in future the solar-wind hybrid option will be the most accepted renewable energy source in terms of techno-commercial viability for off-grid rural electrification projects.

As can be figured, hybrid solar-wind power project are not feasible in non-windy areas; or be used for tasks like water heating, something people associate solar power for. Hybrid solar-wind solutions are almost exclusively used to generate electricity.

Solar-Wind Hydel Power Combination

In India, the solar wind combination is most effective during non-monsoon period during daytime. Solar panels can be interspersed with wind turbines with a common power evacuation facility. It can also complement hydroelectricity, which is mostly at its peak during the monsoon season. Solar wind hybrid power plants can be installed near hydro power to compliment it. This allows for using three different power sources to generate electricity and store surplus power in batteries.

Solar-Wind Hybrid Power Problems 

• Lack of market awareness means solar-wind hybrid systems are yet to become popular in India.
• The initial capital investment is high.
• Less options to deploy as If a house doesn’t receive proper wind or sunlight, deploying a hybrid system is pointless.
• In the house the terrace or the ground has to be large enough to solar panels and wind turbines either together or side by side panels.
• Despite efforts to set up solar hybrid systems, users are skeptical about feasibility of hybrid system
• Ideally suited for deployment only in rural and semi urban areas.
• Very few businessES/vendors are capable enough to design, manufacture, install solar-wind or any other hybrid systems.

Components of Solar-Wind Hybrid System

About Vivaan Solar

Vivaan Solar as a EPC contractor is a solar PhotoVoltaic system installer & integrator. We have installed 60 MW solar park in Madhya Pradesh, 5 MW in Punjab, 8 MW in Uttarakhand and an upcoming park in Karnataka. We are also MNRE accredited channel partner for Rooftop. We have done turnkey works for multiple companies across the country and has third party agreements with some of the leading industries/commercial institutions across the state. We are an MNRE accredited channel partner. For more info you can visit our website: www.vivaansolar.com or contact us at mail- info@vivaansolar.com.

Sources

http://www.thesunworks.com.au/solar_power/solution/hybrid_solar_power_systems
http://energyinformative.org/grid-tied-off-grid-and-hybrid-solar-systems/
www.goingsolar.com.au/what-we-do/solar-electricity-hybrid
http://www.cleanenergyreviews.info/blog/2014/8/14/what-is-hybrid-solar

Can Solar-Wind Hybrid Systems Bring Power to Indian Villages?

http://www.eai.in/ref/ae/sol/cs/tech/hs/spw/solar_photovoltaic_wind_hybrid_system.html