Although Latin America has advanced in renewable energy generation in recent years, the storage issue has not moved forward to the same extent. The conventional view remains one of building electric towers and transformation stations to transmit the electricity miles away from the generation sites, a highly expensive and inefficient option. Emilio Godoy explains.
The use of intermittent wind power and solar resources require mechanisms of storage for times when there is too much or too little intermittent power in the system. In Latin America, Bolivia is taking some first small steps to develop small storage energy systems to support the national grid. The solar plant Cobija in the northwestern part of Bolivia first connected to the grid in September 2014 and has a 5 MW capacity. It is an exciting new project because it has a 2.2 MW lithium-battery storage system.
The solar plant is owned by Eléctrica Guaracachi, a subsidiary of the National Company of Electricity. The project required a USD11,3 million investment, from which the state company invested USD4,98 million and the international Danish Corperation for Development in Bolivia (DANIDA) donated USD6 million.
The plant supplies a total of 54 thousand inhabitants from five towns with electricity. It is a good example of a local energy transition as it shows how small-medium towns can benefit from renewable energy and the expansion of the national grid to areas that have historically lacked access to electricity. The Cobija PV plant already reduces the annual consumption of 1,9 million liters of subsidized diesel, saving the Bolivian economy about USD 1,8 million annually. It also reduces Bolivia’s carbon emissions by 5000 CO2 tons annually.
Bolivia is a fossil-fuel dependent economy. Rich in natural gas, the country relies on the exploitation of natural gas. In 2015, natural gas generated 57% of the 9Thw total electricity generation. Hydro plants were the second largest source for electricity and accounted for 27% that year. Renewables made up 14% of the country’s installed capacity, derived from biomass, small hydro, solar and wind.
Bolivia aspires to change its energy mix significantly by 2025, expanding its renewable energy capacities. The country aims to generate 74% of its electricity from renewables, including hydro. Natural gas will generate more than 30%. The plan is to have around 700 MW come from renewables by 2025.
Bolivia is pushing ahead fast: since 2016, the country’s government has developed at least 10 new renewable projects: 4 solar plants, 4 wind farms and 2 biomass plants. These projects will add 210 MW to the electricity system by the end of this year. Eventually, these plants will also have storage systems.
Based on the country’s 2014 Decree 2048 to encourage clean energy development and the Electricity for Life with Dignity programme, Bolivia intends to foster alternative energies and reach 100% electricity access by 2025.
The country aims for the entire population to have access to electricity, and that most of that electricity comes from renewable energy sources.
The most widely used form of bulk-energy storage is pumped-storage hydropower (PSH), which uses the blend off water and gravity to capture off-peak power and release it during high-demand season. Off-peak electricity is used to thrust water from the lower to the higher reservoir, turning electrical energy into gravitational potential energy. When power is needed, water is released back down to the lower reservoir, spinning a turbine and generating electricity.
The second-biggest technology is compressed-air energy storage (CAES), which encompasses compressing air and storing it in large repositories, such as underground salt caverns. During peak hours, the air is released to drive a turbine, but the process is inefficient and polluting due to energy losses and natural gas consumption for the heating.
One emerging technology is lithium-batteries, like those used in Cobija, which are expensive due to their novelty. Costs may be reduced once their use becomes widespread. The lithium batteries appear as a good option, instead of bigger infrastructure, as that of PSH or CAES, because of its advantages in capacity and efficiency.
Also those systems would have little impact on electricity prices, which, despite hikes in recent years, remain low in Bolivia. In 2014, the average retail price was USD 0.11 kWh. As renewable generation has become competitive vis-à-vis gas, the tendency is to have stable energy prices.
Globally, 149 gigawatts are stored through PSH, from a total of 150 Gw.
Chile, Brazil and Uruguay rank top among Latin American countries in renewable energies, in terms of investments and electricity generation. The Bolivian experiment may offer insights to approach energy storage.
Throughout the region, there are initiatives aiming at the development of those systems.
In Brazil, the official Electricity National Agency already received 29 proposals for the “Technical and commercial arrangements for energy storage systems in the Brazilian electricity sector” R&D project, launched last July and which aims to assess options for the development of energy storage systems and the seeding of such industry. In addition, it should show the way for better integration of renewable alternatives.
The Mexican Energy Regulatory Commission told me that it is studying the most appropriate policy on energy storage, one that avoids damaging renewable generation and burden of costs for enterprises.
Additionally, the Colombian company Celsia, the Argos Group energy division, and the Canadian Advanced Energy Centre, a public-private partnership, formed an alliance to explore choices for energy storage in Colombia, Costa Rica, and Panama.
There are interesting experiments in Canada, Europe, and the US, which, if successful, might enlighten the road for energy storage. Latin America has options to study and apply according to the natural and financial resources available, but the bet is worth taking.
It is on this occasion understandable that the electricity generation of the 5 MW solar plant is described in terms of the population of the locality it supplies. However, that is still dangerously close to the widespread faux pas of describing generation as “enough to power X thousand homes.” – this far into the twenty-first century, a capital offence roughly equivalent to using football fields as a unit of area. For Bolivia, near the equator, it can be surmised that the electricity generated would be between 7 and 7.5 GWhs/yr; but, you know, I would like to see that figure. Call me a pedant, but I want to know its significance in terms of national generation – apparently about .08%. Cultivation of the habit of referring always to MWhs/GWhs/TWhs/PWhs, as relevant, would preemptively take care of other problems, such as occurring later in the article, “…74%…from renewable, …gas will generate…30%.” …?? A new kind of mathematics? Or no, I see: 74% of generating capacity, not as stated, “74% of its electricity.” That misuse of terminology undermines the whole article from that point on. One other thing, much less important: Irrespective of English, American, Irish, Canadian, etc. usage, all Anglophone communities use a decimal point, not a decimal comma, as in continental Europe. It is actually read: “one point five,” and there is no currency for any alternative. (Actually, the true decimal point appeared to disappear decades ago. It used to be placed at mid-height between digits, so in 10.05, it would be between the fat parts of the 0’s. I suppose it fell victim to the limited symbols available on the typewriter keyboard, and to the typesetter. Had word-processing arrived a little earlier, perhaps the true decimal point could have been saved.)