Reactive Power based LCOE Analysis

The renewable energy sector’s growth in the next 5 years is set to skyrocket according to International Energy Agency (IEA) report1 with Solar Photovoltaic (PV) energy technologies leading the way. This high penetration of Solar PV energy being fed into the electrical grid brings in its share of challenges and is making the grid more and more vulnerable, and unstable, which needs a definitive solution.

The presentation addresses one such challenge, of voltage profile improvement with reactive power compensation at the point of interconnection. The main concern is that solar PV plant PPA’s are with a rating of MWac/MWp and not MVA. IEEE Std 1547/UL 1741 compliant inverters will typically not have reactive power capability & operate with a unity power factor. Though modern inverters are, having the capacity to supply reactive power in the range of +0.8 lead/-0.8 lag, albeit the PV plant is rated based on the AC power supplied by the inverter at unity PF. This leads to an inherent error in the per-unit cost calculation, as when the inverter is providing the reactive power the active power is hampered.

The paper highlights a cost base analysis of various scenarios such as inverters working at unity power factor, plants working with capacitor banks compensation, plants working with an excess number of inverters & plants providing reactive power support with small reactive compensation equipment & a small number of extra inverters. It is concluded that the latter case is the most cost effective and economical.

Watch the whole video here.