isolated diesel grids – renewable integration
DESCRIPTION
Marc Mueller-Stoffels, PhD. Isolated Diesel Grids – Renewable Integration. Hybrid-Diesel Power Generation. Diesel-only cost: between 0.35 and 1+ $/kWh Wind in rural AK Average $10,700/kW Large, commercial wind farms: < $3000/kW PV in rural AK We don’t really know the cost yet - PowerPoint PPT PresentationTRANSCRIPT
Isolated Diesel Grids –Renewable Integration
Marc Mueller-Stoffels, PhD
Hybrid-Diesel Power Generation
Diesel-only cost: between 0.35 and 1+ $/kWhWind in rural AK
Average $10,700/kW Large, commercial wind farms: < $3000/kW
PV in rural AKWe don’t really know the cost yetTarget: $5000/kW – makes it commercially viable in many places (@ avoided fuel cost)
NoteDiesel generators: (relatively) low initial investment, but then…RE sources: high initial investment, but then…
Customer RequirementsRural AK sees large variability in demand
Mostly high winter loadsBut, in some places, industry drives high summer demand
Power has to be of decent qualityOutages are always unacceptable
Especially at 50 below
Diesel PowerhouseGenerally:
Provides prime power (forms the grid, i.e., one diesel is always on)Provides electricity AND heatDiesels have sweet spot, outside this, efficiency suffers
Usually pretty well ‘dialed-in’ 100+ years of operation
Cost break-downFuel cost Cost of operationInvestment
Integration of RE – Basic Rules
Operational envelope of diesel generatorsNever under-load diesels (20 to 40%) Do not risk overload (>110%) [keep spinning reserve]Sudden large load swings should be avoided
Without control of RE resourceOnly small amounts of RE power can be allowedExample: distributed PV can quickly become detrimental
Hybrid-Grid Control: Source Management
Curtail RE source to remain in operational envelopeSpinning reserve:
Largest sudden load rise, or amount of RE on grid, which ever is bigger
Hybrid-Grid Control: Load Management
Loads that are controlled by the utility do not require spinning reserve
Examples: Pumps, electric heaters, cooling equipment
Allows operation with less or smaller diesel generatorsMaximizes RE power use
Diesel-off -- Game Changer?
Affordable Energy Storage< 0.10 $/kWh
Need to replace diesel by power-electronics as prime moverDiesel-off mode
Additional 30% fuel savingsReduced O&M costPermanent diesel-off – cheaper diesel packages
And the value of RE power?Displaced Fuel
Not a linear function, but direct savingsReduced O&M on diesels
‘Small’ maintenance can be scheduled based on gallons of fuel used
HedgingVolatile fossil fuel prices are a direct riskRE power can hedge against variation (usually fixed cost)
Questions?
Marc Mueller-Stoffels, PhDResearch Assistant ProfessorAlaska Center for Energy and PowerUniversity of Alaska [email protected]