Common wisdom is that up to 20% renewable generation penetration is relatively straightforward to achieve but thereafter becomes increasingly harder as the penetration increases. The challenges also increase with scale and while 30% penetration has been demonstrated in Germany, up to 100% penetration has been demonstrated on small islands and cities. [Engerati-Put 100% Renewables On The Agenda]
With ever higher targets set in regions and countries at political level the challenge on the ground is how to reach these, and specifically the 100% renewable ‘Holy Grail’, with it clearly involving a comprehensive mix of both utility-scale and business and residential generation, storage, monitoring, intelligence and control technologies along with other actions such as energy efficiency. [Energy Efficiency And Renewables Have Synergies]
One of the first major jurisdictions to ink a 100% renewable target with one of the earliest target dates is Hawaii, which has set the target for 2045 – a mere 30 years away – with interim targets of 30% by 2020 and 40% by 2030. This is up from approximately 21.1% in 2014, according to the latest figures from the Hawaii State Energy Office. The renewable sources are currently primarily bioenergy, wind and geothermal, along with solar, especially distributed PV, increasing rapidly. [Engerati-Hawaii Looks To 100% Renewables]
Towards 100% renewables
The State Energy Office is obviously a lead in the move to 100% renewables, with four stated actions:
• Aligning government regulations and policies with clean energy goals
• Facilitating processes for developing renewable energy
• Deploying renewable generation and grid infrastructure
• Exploring next generation technologies and new applications of existing technologies.
Now a group of vendors have also come together to form the Distributed Energy Resources Council of Hawaii (DERC) as a representative body for distributed and smart grid companies that support the move to 100% renewables. Founding members include energy storage system providers E-Gear and Stem, inverter manufacturers Enphase and Tabuchi Electric, sustainable energy solution provider Hawaii Energy Connection and energy consulting firm Hygrid.
Following the principle and practice observed more and more frequently in the sector of collaboration being more effective than siloed competition, objectives are for the member organizations to work collaboratively towards the common goals and to ensure that they receive reasonable compensation for their contributions. To achieve this DERC Hawaii proposes to act by engaging in Hawaii policy and legislative forums and with Hawaii stakeholders to foster such collaboration.
A 100% renewables system
What will a 100% renewables system architecture look like on a large scale? Some pointers are found in a new report from the International Renewable Energy Agency (IRENA), which presents a five point overview of the transformation of the grid to allow for significant renewable integration:
• Bi-directional flow of energy, i.e. top-down from generators to users and bottom-up with end-users contributing the electricity supply, aimed at ensuring grid stability when installing distributed generation
• Efficient electricity demand and grid management mechanisms aimed at reducing peak loads, improving grid flexibility, responsiveness and security of supply in order to deal with increased systemic variability
• Improved interconnection of grids at the regional, national and international level, aimed at increasing grid balancing capabilities, reliability and stability
• Technologies and procedures to ensure proper grid operation stability and control, e.g. frequency, voltage, power balance
• Energy storage capacity to store electricity from variable renewable sources aimed to increase system flexibility and security of supply.
A smart grid is seen as the ‘enabler’ for this transformation.
Germany’s case also provides some pointers for consideration and the heating and transport sectors are singled out as requiring targeting to increase renewable energy deployment. However, the conclusion that the power sector alone won’t be sufficient to transition the country’s energy system away from fossil fuels is likely to be generally applicable.