DC Nanogrids: A Low Cost PV Based Solution for Livelihood Enhancement for Rural Bangladesh

DC Nanogrids: A Low Cost PV Based Solution for Livelihood Enhancement for Rural Bangladesh

Presenter: M. Rezwan Khan, United International University Dhaka, Bangladesh

Rapporteurs:Seren Pendleton-Knoll and Carmen Iten

Overview

A concept paper, along with cost estimations, is presented proposing the development of very small sized solar PV grids, which we have termed nano-grids. These grids allow the incorporation of developmental activities such as irrigation, along with household usage of electricity. It is argued that the developmental activity should be chosen in such a way that it matches with the seasonal variation in insolation and load demand to keep the energy cost to a minimum.

Issues Discussed

​​► Please see the presentation.

• Bangladesh houses are clustered (15-20) -> larger PV system are ideal (better for costs, easier to handle seasonality etc)
  • Ground water is very shallow in Bangladesh -> weak pumps are sufficient for irrigation
  • PV system and irrigation are a good combination because you can use energy directly without detour over battery during the day.
  • There is a beneficial correlation between power-need and available solar energy throughout the year.
• Lamps number one gadget, but mobile was the most useful. Only mean of entertainment is TV in rural areas. When first introduced, cost was around $7.5 to 8 per watt. Life is short of the battery, system fails only b/c of the battery.
• Switch from batteries to tubular plate batteries. Double the life of the battery. Was for people in the middle of the period, as the bottom of the period can’t afford it. Effective awareness program to show that it is reliable, and cost is comparable to kerosene, but not as much health problems, and can use TV!
• Price of PV starting going down, but price of the battery going up. Now costs are about at par. Once you size the battery, must have the capability to supply energy for 3 days (in the event of cloud). Increase size of PV panels have the opportunity to reduce the size of the batteries.
• Giving an opportunity for the agriculture sector to have economic growth.
• Keep products for 2 weeks in short term storage of perishable agro products. Save them at least 25-30% of production cost. Stops most of the money going to the middle men. During cropping season, hiring labor is a headache, any sort of rural transportation with battery can be helpful.
• DC is the system that is going to come.
• More hopeful about the nano-grids as cost is less. More nano than mini grids.

Q & A

1. How many irrigation-nanogrids in reality?

• No irrigation-nanogrids so far but the first should be installed soon. It is only a model so far.
  

2. How can you couple the pv system to irrigation?

• Restriction on load capacity.
• Costs: Meter cost is 50% of costs. But it is necessary to manage the surplus of energy. They have fixed charges for the meter to ensure the economical sustainability of the company.

3. Can you use same approach in different environments?

• High population density is needed for the model to work.