Controllable CGS, Smart Export or Zero Grid-Buy, Which is Best for Isolated Island Residences Like Hawaiʻi for Cost Savings, Next Island Blackout and Achieving State Goal of 100% Renewable by 2045?

Abstract: The recent September 20, 2017 Puerto Rico hurricane destroyed the centralized utility grid power leaving the island without power to its inhabitants for months shows the need and value of 100% renewable energy for single and multi-unit residential homes with optional off-grid operation in Hawaiʻi. On Oʻahu there are ~48,000 net energy metering accounts as reported in the Honolulu Star-Advertiser 11/21/17 on page B4 and a 10x drop in solar permits since peaking in 2012. With 1/3 of homes on Oʻahu having rooftop solar-PV, all the export back to the grid created the HECO “Duck Curve” problem starting in 2013. The utility Duck Curve problem in CA has resulted in the shifting of mandatory TOU (time of use) rates from peak solar generation afternoon time to early evening non-solar generation periods (4PM to 9PM) and requiring smart inverters so they can curtail rooftop PV- generation during the day when needed. They also reduced PV export credit rate to just 10¢/kWh resulting in a 41% drop in rooftop systems this year in CA. In 2015 Hawaiʻi ended the full credit retail rate for NEM to achieve Zero Net Metering and currently TOU peak rates from 5PM to 10PM is optional not mandatory. The current controllable-CGS (customer grid supply) with day time export credit rate of 10¢/kWh requires smart inverter for PV generation curtailment control by HECO and Smart Export with night time battery export credit rate of 15¢/kWh makes residential rooftop solar-PV less attractive with much longer payback (ROI).

Also, because of HECO’s Duck Curve future solar-PV farms and CGS with daytime export back to the grid should not be allowed and why daytime DER benefits to the home owner and HECO are confusing with all this excess day time energy generation. Instead a new policy/program targeting Zero Grid-Buy for all future rooftop solar-PV + multi-storage with no export back to the grid should be mandatory and the HECO monthly minimal TOU service connection fee reduced from $17.00/month to $5.00/month. This will allow <3 years ROI and drive the future growth of residential solar-PV market. Therefore rather than require new home building energy codes as reported in the Oct 2017 issue of Wiliki, the residential home solar-PV market can drive and achieve the state goal of 100% renewable energy “Today” years ahead of the 2045 date if 50,000+ new homes are designed for solar energy + multi-storage to achieve Zero Grid-Buy. Each panel member will discuss their views/experience on residential rooftop solar-PV, utility scale DER, state policies or home building energy codes and what is best for isolated island like Hawaiʻi for cost savings, pro-active to next island blackout caused by Mother Nature and achieve the state goal of 100% clean electricity by 2045.

Panel members:

1. John Borland moderator and home owner with rooftop solar-PV + multi-storage discussion on CSS (customer self-supply) with no-export, Zero Grid-Buy & Off-Grid residential solar-PV case study on cost savings.
2. Guest panelist Professor Tseng King-Jet of Singapore Institute of Technology, Singapore discussion on their plan to establish a new 10MW microgrid which is utility interoperable and islandable with multiple energy sources. This will help Singapore in the transformation of its conventional centralized utility grid into clusters of resilient autonomous district-scale microgrids.
3. Howard Wiig State of Hawaiʻi Energy Office discussion on home building energy codes and what homes can do to achieve the state goal of 100% clean electricity by 2045.
4. Ian Morikawa of HECO discussion on how DER works and the value/benefits to HECO and home owners based on current controllable-CGS, Smart Export and CSS programs.
5. Keith Webster home owner with rooftop solar-PV discussion on NEM residential solar-PV case study on cost savings.
6. Jay Moore of Poncho’s Solar discussion on controllable-CGS and Smart Export examples on how to maximize payback and cost savings.