Wind and solar as part of renewable energy, should be optimized in order to balance world vast growth in energy demand.
Driver of Renewable Energy Development
Stabilizing climate impact by reducing carbon emission from fossil fuel use.
Ensuring stability and security of energy supply to all part of the countries.
Abundant and sustained energy resources.
Expanding energy access by providing electricity to the society without energy access.
Acceptable economic investment due to zero fuel costs hence declining average energy costs over time and protecting assets from fuel price fluctuation.
MBIE report in 2013 reported …show more content…
The electricity is transmitted through grid which consists of 200 kV, 110 kV, 66 kV HVAC and inter island 1200 MW HVDC. HVDC installed from Benmore power station in the South Island to Haywards substation in the North Island
Non controllable variability Wind and solar output varies as uneven wind speed and erratic sun lights which may affect power output hence will require additional instantaneous basis energy supply, frequency regulation and voltage support. In second-to-minute scale, unchecked fluctuation of frequency and voltage can harm the system and equipment, thus grid operator may order generator to inject active/reactive power to stabilize actual and forecasted power, which is important to maintain grid frequency and voltage.
Partial unpredictability Different with variability, this uncertainty refers to the inability to predict wind/sun availability in hour-to-day basis, which is significant for grid operator to manage so called unit commitment (process of scheduling generation in advance in order to balance the demand). Inconsistent weather condition can cause deficient of electricity generation hence additional standby reserves is needed, nonetheless it side can also produce excess energy thus oblige other dispatchable load when generation is more than …show more content…
This effect carried out when amplitude of each phase voltage is not exactly 120o. if this occurred on single phase DG, it may cause unbalanced networks which could lead to damage of transformer.
Voltage rise and reverse power flow. With significant levels of DG, localized overvoltage can occur. Voltage rise happens when the voltage of the load is higher than the supply side.
Power output fluctuation. This is caused by fluctuation of resource, where it requires back up generation to maintain power supply.
Power factor correction. Poor power factor correction increases line losses.
Frequency variation and regulation. In maintaining power quality, frequency is controlled by maintaining balance between connected loads and generation. DG inverter could solve this problem by provide frequency control in milliseconds
Harmonics. This is can be managed by installing inverter which correcting harmonics.
Unintentional islanding. This effect occurs when distributed generation delivers power to networks even after circuit breakers have disconnected that part of the networks from main grid and associated generator. This can be minimized by employing grid inverter technology which includes anti-islanding features.
Solution to PG-DG