The intermittent quality of renewables electricity generation has long been highlighted as a major limitation to the global expansion of renewable energy, particularly for those countries that consider technologies , such as solar and wind , fundamental to their long-term energy security. As such, the development of residential electricity storage batteries provides a promising solution to the issue . That said, we highlight the high costs and small-scale nature of the batteries as major barriers to the widespread adoption of the technology.
Renewables Heading For Bottlenecks
The principal technical limitation of renewable- based electricity generation is its intermittent nature, most notably with s olar and wind- sourced power ( i.e. , when the wind ceases to blow, electricity generation also stops). This presents a major bottleneck for the global renewables industry, particularly for countries who have adopted energy policies that revolve around renewable energy expansion. For example, countries in Europe, that are bound by the EU climate and energy package and the EU's ' National Renewable Energy Action Plan ' (NREAP ) , are finding it increasingly difficult to integrate high levels of renewables into their electricity grid.
Italy, Germany and Denmark have some of the most highly develop ed renewables markets in Europe (based primarily around solar and wind) and have extremely ambitious targets to m eet . Italy aims to expand its renewables industry so that it contributes just over 26% for electricity generation by 2020, 35% for Germany by 2020 (80% by 2050) and 35% by 2020 for Denmark as well (100% by 2050). However, issues with the conventional European grid and inefficiencies with the power network in these countries, particularly Germany, have so far hindered the industry's growth. For renewables to play a fundamental part in ensuring the long-term energy security of Europe, combating the intermittency issue will thus be crucial.
Battery Storage Gaining Momentum, But Challenges Ahead
A solution to the aforementioned problems is the development of electricity storage batteries, which wou ld help align supply with demand by storing excess renewable-sourced electricity until it is required. In fact, the use of residential solar batteries is gaining traction in some countries already, chiefly Japan, Italy and Germany. These batteries tend to be installed in homes and small business, connected to a solar panel, and then on the grid through an inverter.
Although promis ing on paper, there are still a number of factors that we have identified that could threaten the development of the battery storage technology:
Solar batteries are expensive, both to buy and install. According to an article in Reuters, an average 6KWh battery costs around US $ 6,500, plus additional installation and conne ctivity costs. Although, it is thought that the technology costs will reduce considerably over the next few years (on par with the trend of falling technology costs of both solar panels and wind turbines) the initial financial burden of the battery is likely to present a sizeable barrier to cash- squeezed European households, who are already facing the prospect of higher electricity prices on account of su bsidising renewables.
|Polysilicon $/kg And Bloomberg Wind Turbine (EURmn/MW)|
Large-Scale Feasibility Questionable
The batteries currently being used for storing solar electricity are suitable at the residential level, whereas large-scale battery storage technology is still in the process of development. Research into utility-s ized batteries is being undertaken in a number of countries ; however, the technology is still far from proven. For example, the US Department of Energy (DoE) announced in late 2012 that it will channel US$120mn in funding to the Joint Center for Energy Storage Research (JCESR) over the course of five years to research the development of large-scale electricity storing batteries.
Despite these challenges, we do expect small-scale residential solar batteries to grow in prominence within the renewable energy industry, particularly in well-developed European markets such as Germany, Italy and the UK. Germany has already stated that it will support a roll-out in solar battery installations with at least EUR50mn worth of credit lines, and we expect to hear increased rhetoric on the topic over the course of the year.