Developement of Optimization Method/A Tool for RE applications in Intermittent Grids with focus on Lebanon
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Renewable energy applications require sound design and optimization of life cycle costs because they need upfront investments and as long as possible operating lifetimes are expected. Using modern tools for optimizing designs of grid-tied and autonomous plants allows investors to deploy these technologies while keeping risks within acceptable limits.
Nevertheless in Lebanon, the grid is intermittent and the most adapted solutions are dual-mode plants that can operate autonomously and with grid-tie. There are no existent simulation models particularly adapted to optimize these applications for such a situation. The objective of this research is to suggest and test a model adapted from commercially available software that can simulate the particular conditions of Lebanon. The studied solution has a PV generator associated with a PV charge controller, lead acid battery, a dual mode inverter, and transfer switchgear and protections. The research successfully met the objective of finding a setup in HOMER 2.68beta for simulating and optimizing a PV-Battery AC plant for an intermittent grid with scheduled blackouts.
The setup and adaptation in HOMER is made to replicate an existing reference PV-Battery plant at a public school. The measured data from this public school is used to validate the results obtained from the adapted HOMER simulation. The grid is supplied for an average of 12 hours per day at the reference site with a tariff of USD 0.1/kWh.
After the validation process, a sensitivity analysis is performed to simulate this plant under
- Different grid supply hours, 12 and 18 hours of supply daily
- Different grid electricity prices, USD 0.1 and 0.1375 /kWh
- Simulation of PV plants to meet other load profiles typical of community and municipality building centers
All the simulations cross matched 20 different PV generator sizes to 7 different battery sizes for 5 different total setups.
The levelized cost of electricity, COE, is the main parameter used to find the optimum setups, whereas options that shortened the battery life to less than 12 years or couldn’t meet at least 90% of the required yearly load were filtered out. The COE is calculated manually since several corrections related to grid and net-metering limitations are not obtained directly from HOMER.
The simulated results can serve as a good indicator on how the systems would perform for typical public institutions in Lebanon, given the current conditions, and knowing that the range of this study is limited to small scale institutions with consumption levels less than 30 kWh/day. Storage capacity should also be limited to 100 kWh/day of useful storage, since batteries are not the best option to use for storage capacities higher than the mentioned limit.
The setup has a great potential for advancement and acts as a first step for Lebanon to have a specialized tool for simulating the performance of PV-battery AC plants optimized for the conditions existing in the country. Future steps could be made to improve and diversify the software to include:
- irradiation data that come from actual data logging data from other PV sites which are installed around the whole country, almost a 100
- financial analysis for offsetting private generation with fossil fueled gensets, which is the main backup for electricity blackouts
- wind turbine simulations, several installations are provisioned to be completed by the end of 2012, and it would be possible to carry out a similar validation process for small wind turbines
- pollution and other environmental costs
- value of lost load, “VOLL”, to compare different options in parallel with COE.
Place, publisher, year, edition, pages
2012. , 67 p.
Renewable Energy, Optimization Software, HOMER, Intermittent Grid, Lebanon
IdentifiersURN: urn:nbn:se:kth:diva-101805OAI: oai:DiVA.org:kth-101805DiVA: diva2:549755
Master of Science - Sustainable Energy Engineering
2012-09-04, HPT Library, Brinellvägen 68, Stockholm, 10:30 (English)
Vadiee, Amir, Lic. Tek.Vallve, Xavier
Martin, Andrew, Professor