Run elevators, pumps, lights, with Solar & Save Big
Contribute to Environment
MANAGED ROOF TOP SOLAR
Rahul Sankhe, non ex Director
IIT-B, MS (UTA), ISB
Distributed Clean Energy can transform the Energy landscape
Heramb Ranade, Director & CEO
Electric Mobility powered by clean energy is a win win for all stakeholders
Vignesh N, Angel Investor
IIT-M, MS (WU), ISB
Urban Buildings can benefit big from clean energy, right now
We deliver clean energy solutions and services to Urban Buildings. Our vision is to generate maximum clean energy with roof top solar plants, to not only power the common utilities but to also cater to the future energy demand of electric mobility. Displacement of polluting gensets with battery storage is yet another program we will work upon, among others, to realize an end to end clean energy value chain
SPECIALIZED SOLAR PLANT SOLUTIONS
FOR URBAN ROOF TOPS
Conventional solar plant design approach, widely adopted by suppliers, is grossly inappropriate for urban roof tops which are subjected to significant shading caused by tanks, walls, fancy structures and nearby high rises. This invariably ends up in sub-optimal performance and
lower return on investment
Skybless has developed a specialized practice for roof top solar plant design, execution and life time management, and this helps us to guarantee performance and
deliver projected returns
Tel. +91 91377 08359
Office: 702 A Wing, Symphony IT Park,
Chandivali, Mumbai, 400 072
Frequently asked questions
What does SkyBless do, what does it offer?
In the initial phase SkyBless shall work with group housing and shared commercial buildings in cities to deploy roof top solar for powering the common utilities such as lifts, pumps, lighting. The same infra, in future, can power the electric vehicle charging stations that Skybless would set-up in these buildings.
Skybless offers both CAPEX and OPEX based solutions and services for its roof top solar offering.
Which problems is SkyBless Solving?
There are certain hurdles which restrict the urban residential and commercial buildings to benefit from clean energy opportunities. The affairs of these buildings is run by bodies known as society managing committees or RWAs comprised of residents/occupants who work on a voluntary and honorary basis. Unlike an industrial or large office establishment, they lack in-house engineering or maintenance resources, domain knowledge, time, skills, and tools to plan for and later manage any complex energy infra.
Why should we install a Solar Plant on our rooftop, what are the benefits for us?
Solar can power the common utilities in your building such as lifts, water pumps, common lighting, and others. If your electricity consumption on common utilities is more than 2000 units per month on average, then roof top Solar with net metering is an attractive proposition and investing in the same should deliver you a return on investment of 20% or higher, after accounting for the operations expenses, taxes, duties and infra management fees, that too without any subsidy support.
How much area is required for the solar panels/ plant? Which factors affect generation other than area ?
One sq ft can potentially generate 9 to 11 watts per sq ft. Area required is a function of capacity. E.g. A 20 KWp plant capacity will need 200 sq mtrs or roughly 2000 sq ft of shade free space on your terrace or roof.
How much do the solar panels/ modules weigh. Can they cause harm to the structure?
The modules along with their mounting structure generally weigh less than 60 Kg per mtr square. This is an ordinary load for a RCC structure that has about 2000 sq ft or larger roof top space. Modules are generally placed on the roof floor, water tanks or lift room tops, which do not require any further reinforcement.
What are the key variables that determine energy production? How much energy is produced from a typical solar rooftop plant?
The energy generation or yield from the installed capacity depends on:
(a) Amount of sunlight (irradiance) received during the year, temperature, dust levels, shading, air-flow, most of which are linked to the location or city where the system is installed
(b) Type, Grade and Quality of modules, Inverter sizing, quality of design, quality of installation, module cleaning quality and frequency
(c) Tilt and orientation (azimuth) of the modules; and also whether it is a fixed tilt, or variable tilt using single axis / dual axis trackers
(d) Presence of optimization devices used to deal with mis-match loss due to intermittent shading and non-uniform degradation of modules during the plant lifetime.
If the solar modules and associated equipment are of good quality, modules are regularly cleaned, and each module is monitored for its performance then one can achieve optimum generation. All of this is possible only if there is a daily monitoring of the system which also helps to achieve high uptime. The agency undertaking such an activity needs to have the domain knowledge and requisite measurement and monitoring systems. A drop in the yield can reduce or even wipe out all savings and render the investment unviable.
Is the energy production impacted by ageing of the plant?
Yes. The drop in yield in the first year is typically about 2.5% of the original rated module power and the yield falls @ 0.8% to 1.5% every year from the second year onwards. Typically, only about 70% to 80% of the original rated capacity is retained by Year 20. This should be factored into the savings calculation, and the ROI analysis.
Degradation can be far worse than the normal range, if modules are of inferior quality or they are installed in shade or not cleaned regularly.
What happens when there is no sun or on a cloudy day? Will our lifts function ? Can we use our gensets or batteries along with the Solar system.
The energy generation is reduced during periods of low sunlight i.e. in early morning, evening, cloudy weather, etc. However, since the Solar Power is grid tied, it does not matter how much power is being delivered by the Solar Plant, as shortfall if any is bridged by the DISCOM supply, the same way it happens every night. So all your utilities continue to function normally as long as the DISCOM supply is available.
During periods of DISCOM outage, a grid tied Solar power system is required to shut down as mandated by the grid islanding guidelines of the regulator. The genset or batteries are required to operate the electrical loads, in an islanded mode, when DISCOM power becomes unavailable . You have the option of operating the Solar Plant even during DISCOM outages by obtaining reference voltage from the batteries or genset, but strictly in an islanded mode only.
Do we still need the DISCOM supply?
Yes. The Solar energy production is primarily based on the amount of sunlight, which changes during the day and with seasons. The purpose of the solar rooftop is not to remove the DISCOM connectivity but to supplement it while reducing overall costs. If the total peak load is higher than the rated solar energy capacity then even on a sunny day when the Solar generation is at its peak, we would need to supplement the shortfall from a DISCOM or back up source. Genset and Energy Storage can technically obviate the need for a DISCOM supply but that will come at a very high cost and effort. DISCOM supply will always be needed.
Do you provide batteries? When are batteries required ?
Batteries are not required in a net metering arrangement. The additional investment in batteries, impacts commercial viability of the project. Battery backup can be an alternative to gensets, provided the peak power demand and energy units required during the longest expected DISCOM power outage can be catered to by the installed battery capacity.
Batteries may be considered and can be integrated with the Solar plant, as a power back up option or to store surplus energy generated by the Solar plant during certain periods of the day for use later in the day, subject to compliance with grid islanding.
What is net metering?
Net metering is an option that the DISCOM provides to allow you to send the extra power to the grid in exchange for banked energy credit that you can use when you need it. When your building/home is equipped with a renewable energy source (such as wind or solar power), it can send the excess energy that's generated back into the grid.
As that excess energy is transferred to the grid, your power meter spins backward rather than forward, giving you a credit that you can use to pay for your future energy use. You can roll over excess credit at end of the billing cycle to your next bill, but not beyond the financial year.
Is there a business case to export energy to the grid
If you are a net-exporter to the grid at the end of the financial year, your DISCOM or electricity company pays you for the net-exported units at their average whole sale cost of buying energy, which is less than half of that you save when you bank the energy credit. Net-Export does not earn you any return when you factor the cost of capital and maintenance costs incurred on the Solar Plant.
Can we get net metering?
Net Metering is available in the state of Maharashtra, as also in some other states, and DISCOMs are mandated to provide net metering to aspiring consumers. However this policy may get revised and one needs to check the prevailing policy at the time of planning the Solar or RE project.
The DISCOMs have Renewable Power Purchase Obligation which require them to maximize the power they purchase from renewable generation units. However, whether the consumer can get net metering is subject to the Solar capacity being setup, the sanctioned load, distribution transformer capacity of the DISCOM and such like factors. The electricity regulatory authority in each state in India has published a net or gross metering policy which governs net or gross metering arrangements between DISCOM and Consumers.
What is our investment?
The investment for the Society or Building is dependent on the commercial option exercised:
1. Capex Model: Approx. Rs 12 lacs for every 20 KW capacity. Capex per KW falls as capacity increases. Additional CAPEX may be required to make the roof structure suitable for Solar Module mounting and the same shall be over and above the above indicated value.
2. Co-Invest Model: Same as above, except that the building has an option to invest only a portion of the total CAPEX, generally in the structural costs and towards items that are custom designed for the building such as cables, fixtures, etc. The rest of the (movable) infra investments are made by SkyBless. The net returns are shared in the same proportion of the investments after deducting all infra management costs, consideration amount for roof usage, insurance, taxes and duties.
How much can we save? How are the savings computed ?
Savings is dependent on (A) capacity, (B) yield or energy generation delivered by the installed capacity, (C) gross unit cost of electricity applicable to the meter to be interconnected with the Solar (or renewable energy) system.
Each of these factors are further dependent on other sub-factors, as stated below:
A. Capacity of the system, feasible for installation depends on:
1 available shade free space
2 sanctioned load on the meter/s to be used for net-metering
3 the consumption on the meter/s
B. The factors impacting energy generation have been discussed in an earlier question in details.
C. The gross cost of electricity consumed by the electrical loads depends on:
1 Consumption slab, Consumer category and DISCOM tariff
2 The levies and surcharges applicable such as wheeling charges, regulatory asset charges
3 Duties and taxes such as electricity duty payable to DISCOM and that applicable for renewable energy for self-use, tax on sale of electricity, GST if any (presently nil).
Net Savings = No of units delivered from Solar x Gross Savable cost per unit, minus sum of (opex + duties + insurance)
Detailed workings over 15/20 years need to be done to estimate savings reliably, once above inputs are available.
What is the life of the plant?
Solar Modules are usually rated for 20 to 25 years of operation. It is important to check the manufacturer’s specification sheet. Balance of systems such as inverters, cables, structural elements, may need repairs, replacements or refurbishment at least once during every 6 to 8 years.