Project Title: Low-Cost Home Solar Power Kit
Problem Statement: Many homes in Pakistan experience 8-12 hours of load-shedding. As solar power becomes more cost-effective we want to develop a low cost solar kit intended for households with low monthly electricity consumption, by providing 30-90kWh/month of electricity from solar power. The kit will be based on one solar panel, a storage battery, inverter, charge controller, mounting stand and standardizing wiring related items needed for installation at existing homes.
System Price Target: Rs 70000- 120,000 for material. Rs 10000 labor (assembly and installation of kit)
Solar Panels: Minimum of one 250W panel – to just operate a fan and light bulb, to using three panels for total of 750W power generating capacity. Panels are polycrystalline Silicon. Efficiency of 15%. 25 year life panel.
Battery: Storage capacity of 1.5-3 kWh (or 100 to 300 Amp-hr using 12VDC batteries. Useful life >1000 cycles. Temperature rating (<10% drop in performance)
Charge Controller and Inverter: Pure sine wave inverter
Mounting Stand: Pole mount or rectangular metal frame. Ability to bear the weight of the panel and related items. Ability to adjust tilt (winter vs summer) and also rotate Eastward or Westward to take advantage of sunlight in morning and afternoon. Ability to access panel for cleaning the surface.
One system consisting of 750W of solar panels and 200Amp-hr of storage has been installed at NED for prototype testing in May 2017. System is currently under test to identify the determine the performance at various price points e.g. Rs. 50000 will only operate a fan and light, and charge mobile phone for several hours every evening, while a Rs 140000 system can also handle a fridge. Bill of Material, list of suppliers and pricing, as well as detailed assembly and wiring instructions with images uploaded on sawayra.org as all projects are open-source to maximize deployment.
Solar system design – Dec 2016
Finalize detailed design by August 2017 via market study to identify cost effective sources for partsand local requirements in Karachi slum areas, kachi adabis and low income areas such as Orangi, Korangi etc. Procurement completed by August 2016. Assemble kit at university and collect data for a week in terms of power generated and set-up. Finaliza design by Dec 2016, and plan deployment of pilot test units for March 2017.
Technical Project Manager: Aqil Biabani (firstname.lastname@example.org)
Project Team: The project team consists of four interns from NED. They are Muneeba Asif, Rais Badshah, Asma Naz, and Hassam Uddin.
Appendix 1 – Additional Background
Once the prototype phase is complete, step two will be the pilot project phase where the kits are installed for 10 homes on zakat or qarz-e-hasana basis. For the purpose of assembly and installation of the additional solar kits, students will training the students at the trade school in Rashidabad, so they can take over the project. For each kit, the home owner will be asked to pay Rs 5000 upfront pay off the balance of equipment and installation cost over two years, so the seed money can be directed to the next set of homes and so on. The partial payment also helps ensure that the home owner takes care of the kit via keeping it clean and secure. We plan to start this pilot project phase in Spring 2017.
Survey underway at Karachi to determine household electricity consumption and appliances that are used. Current information targets running two fans overnight (50W each), and supplying two LED lights that can run for 4 hours every evening (consuming 8-10W each). Additionally, the household can charge one or two mobile phones and run small LCD television or radio for 4 hours every evening. These should not exceed 1 kWh of electricity usage every evening. Current retail pricing of panels in Karachi is about Rs 10000 per Watt, but the landed cost would be between Rs 3500 to Rs 5200 depending on quality of panel (A – no manufacturing defects. B – minor manufacturing defects). Sister projects are intended to provide more details on current technology available in Pakistan with respect to panels, charge controllers, inverters and batteries. A number of items (fans, light-bulbs, radio etc.) can also be run on DC, but line losses/cost of thick wiring may make it better to use inverter and simply convert DC from panel to AC for home use.
The kits is not intended to run refrigerators, ACs, and any devices that draw a lot of power. As such, it is targeted for low income families
Appendix 2 – Tables and Charts
Figure 1. Global solar insolation map showing incident energy in kWh per square meter of surface area
|Total Energy Consumption
|12-V LED light bulb (equivalent to 75-W incandescent light bulb)||9||0.036-kWh for four (4) hours of evening usage|
|AC fans typically use 25-75W. Use lower power fan. 12VDC fans 12inch size will use about 25W||25-50||0.3-0.6kWh for twelve (12) hours of nighttime use|
|Mobile Phone Charger||4||0.015-kWh for four (4) hours of use|
|Refrigerator (14-ft3) with Star-rated efficiency (will need AC power)||75||35-kWh per month|
|Iron for clothes||1,500||1-kWh per hour of use|
|Laptop computer||30||0.12-kWh for four (4) hours of evening usage|
|15” LCD Television||25||0.075-kWh for three (3) hours of evening usage|
|Small Radio||8||0.025-kWh for three (3) hours of use|
|Washing Machine (for clothes)||500||0.5-kWh per load|
|Small Air Conditioner (will need AC power)||1,000||1-kWh per hour of usage|
Table 1. Energy consumption of various household appliances (per second) and over a typical period
Figure 2. 300W 12V DC to 110V AC Inverter (USD 30) with two outlets and 75W 12V DC to 240V AC Inverter (USD 10) with one outlet. Both available in US from amazon.com.
Figure 3. Solar Panel Module prices – (Euro/Watt) by region of manufacture (1 Euro = PK Rs 112)
Figure 4. Typical 12-V battery prices in Pakistan in 2015 (1-kWh of storage is 84- AH (ampere-hours))