Sunday August 18 Germany set a new renewable record. That day at 2 pm generation from renewable energy sources provided 75 % of all power needed to satisfy the total demand of electric energy.
Less noticed was that Burlington Electric Department, Vermont, in September with the purchase of a 7.4 MW hydroelectric facility achieved its goal of reaching 100 % from renewable energy.
While Germany’s August 18 record was a peak, Burlington’s 100 % is basically on a continuous basis.
What makes Burlington Electric’s achievement additionally impressive is that retail electricity rates in Burlington are less than half of the rates in Germany, 13.7 cents/kWh (time of use rate 2014) versus 36.25 cents/kWh (average 2013).
Germany operating at up to 80 GW is more than a 1000 times larger electric system than Burlington operating at up to 60 MW. Consequently, one has to be careful when making comparisons. Nevertheless, there are similarities as well as some significant differences.
The main reason for the high electricity prices in Germany are the high costs of the subsidies (presently about $24 billion a year) for the massive expansion of wind and solar. At the time of the peak 35 % of the power came from wind and 25 % came from solar, but accumulated over the year (2013) wind and solar deliver “only” about 16 % of the electric energy (still an impressive number).
In Burlington Electric biomass and for most part hydro are base-load generation. On average (2012) biomass delivered 33 %, hydro 7 % and wind 9 % of the power.
Germany with its focus on wind and solar as their primary renewable energy sources have to balance the intermittent nature of wind and solar with a large fleet of coal power plants and extensive exchange with neighboring countries. In fact the first hour of August 18 the coal power plants produced about 24 GW, of which 2 GW was exported. At 2 pm, when the renewable record was set, the coal plants were only ramped down to about 17 GW, of which about 7 GW was exported. In fact as the renewable energy in Germany has increased so has the export of power generated by its coal power plants. For the importing neighboring countries the feelings tend to be mixed. The price of the coal may be low, but it comes with the CO2 and other emissions as well as grid stability challenges.
Like Germany Burlington Electric also works with surrounding systems through New England ISO (Independent System Operator). Until the acquisition of the hydro power plant Burlington Electric was a net importer. Going forward it will on average be about net zero. When exporting it will come from its renewable energy sources.
Assuming the primary reason for pursuing more renewable energy is to reduce CO2 and other greenhouse gases, it is important or even crucial to have a large portion of the base-load generation at zero or very low CO2. Hydro, biomass and biogas as well as geothermal meet this criteria. So does nuclear. However, the latter option is being eliminated in Germany due to strong public support of the decision to phase out nuclear. Instead the base-load generation is mainly by coal (53.3 % of all energy produced in 2013)!
To manage large amounts of intermittent renewable energy like wind and solar one needs access to flexible resources such as hydro and gas turbines, preferably combined cycle for high efficiency and low emissions, energy storage as well as strong transmission systems in order to exchange power within the grid and with neighboring systems. The larger the footprint the easier to balance the intermittent energy sources.
Consequently, it makes sense that Germany plans to expand its domestic transmission system with four additional north-south HVDC (High Voltage Direct Current) transmission lines as well as a new HVDC link with Norway (hydro).
Germany with its ambitious and costly Energiewende program targets to reach 60 %of its electric energy from renewable sources by 2030.
Burlington Electric has reached 100 % now!