Common wisdom is that up to about 20% penetration of intermittent renewables such as solar and wind can be accommodated in the electricity system without problems. However, above that level the challenges increase and integration requires new flexibilities such as demand side response and energy storage.
Germany has demonstrated the way with an average renewable penetration of 33% in the last year – and up from 27% in 2014 – according to the German energy think tank Agora Energiewende. However, for short periods even higher penetration levels have occurred, the most recent a peak of 82% on May 15.
100% renewables electricity
But for an increasing number of countries, 100% renewables is the target. [Engerati-Put 100% Renewables On The Agenda] And it is possible, at least for relatively short periods at this stage – as Portugal has recently demonstrated. According to a statement from Portugal’s Sustainable Land System Association (ZERO) an analysis carried out in collaboration with the country’s Renewable Energy Association (APREN) found that Portugal ran on renewables for a total of 107 hours, from 06h45 on May 7 to 17h45 on May 11.
While the breakdown of the renewables contributions isn’t specified, Portugal’s renewables are dominated by hydropower (5.7GW) and wind (5.1GW) with just small amounts of solar and biomass (approximately 0.5GW each, all 2015 figures).
“Renewable electricity production and the Portuguese electricity grid management capacity passed a difficult test against a background of limited interconnections, especially between Spain and France,” the ZERO statement reads.
ZERO goes on to comment that if such an achievement can result from the rains and winds in the spring, then more effort should be put into harnessing energy from the sun in the summer.
“This data shows that Portugal can be more ambitious in the transition to a net consumption of electricity from 100% renewables, with huge reductions in emissions of greenhouse gases.”
Currently Portugal produces about 50% of its electricity from renewable energy sources and is on track to reach its 60% target by 2020.
Iberian Peninsula interconnections
The limited interconnection capacity of the Iberian Peninsula has been highlighted as a major obstacle for the creation of a regional electricity market in southwest Europe. [Engerati-France And Spain Gain Key Electricity Interconnection] New interconnections between Portugal and Spain and Spain and France have been proposed as transmission priorities. In addition, several network reinforcements have been identified in Portugal to facilitate renewable integration. [Engerati-Ten-year forward look to Europe’s transmission networks]
Alongside the need for interconnections, the International Energy Agency’s 2016 review of Portugal’s energy policies identifies two additional key recommendations for the country towards the development of a sustainable energy system.
According to the review Portugal has continued to develop and reform its energy policy in recent years. Benefits have included greater economic activity in the energy sector, rapid increases in renewable energy deployment, further market liberalisation in the electricity and natural gas sectors, and greater emphasis on energy efficiency in policy making. Revised targets in the revised National Renewable Energy Action Plan (NREAP) are a 25% reduction of primary energy consumption nationally and a 30% reduction of energy consumption in the state-owned sector by 2020, alongside the renewables target.
Further needs are:
• To continue to implement measures to ensure that there is sufficient flexibility in energy policy to deal with uncertainty in demand growth and wider policy development at the EU level. This policy process should accommodate regular independent reviews and the development of a monitoring tool to examine implementation of energy policy and ensures that it continues to remain relevant and cost-effective.
• To ensure implementation of measures to reduce the tariff deficit, estimated by the regulator at €4.69 billion at the end of 2014, which was caused by past imbalances between the electricity system’s regulated costs and revenues from regulated tariffs, and to continue efforts to identify further potential cost saving measures in the energy sector. In this regard, consideration needs to be given to the decision to extend phasing out of regulated tariffs to 2017.