Green energy has always been associated with increased costs. Somehow the system of generation and distribution of power convinced consumer and government alike that whatever is good for health and the environment requires a premium. How often are we not requested to perform a cost benefit analysis that amounted to business as usual? The classical management adagio of “core business and core competence” lead to the imposition of the economies of scale, based on few energy sources aimed to reduce the cost per kilowatt hour (kWhr) for the producer. The energy mix today is driven by the capacity to respond to base load and peak demand at predictable rates with guaranteed margins, passing the additional cost on to the client. This resulted in the adoption of nuclear, coal, fuel and natural gas as the core sources. Renewables were typically dismissed since - as the argument goes - the sun only shines 5 hours per day, and wind is unreliable. Then renewables need back-up and storage. This increases the cost borne by the customer or requires subsidies from (bankrupt) governments which in the end are also paid by citizens through higher taxes.
Time has come to reassess this logic. There are two guiding principles of The Blue Economy that determine the identification of a new energy mix beyond green power. First, use what you have. Second, search for multiple benefits. To succeed in this endeavor requires a change of the rules of the game. It has been widely overlooked that our grid today distributes power at 240 V in alternate current (AC). Nearly all renewable energy is generated in direct current (DC). The integration of DC into the grid requires additional capital. If we were to create local 12V DC grids, then many well known but little used renewables would immediately become economically viable without major investments.
The AC enigma made us neglect the potential of all renewables. Photovoltaic cells are only used on one side, even though these could generate more power when sun light is exposed on both sides, especially when concentrated solar is applied to the bottom. If this power were fed straight into a 12V DC local network, then it would outcompete the power supplied by the grid. Unfortunately, electric engineers have been groomed in the AC logic, and off-the-grid homes or communities have been equated with investments in back-up batteries, increasing the cost to the consumer beyond reason. Only the very green and wealthy could afford this option.
Anyone committed to renewable energy produces predominantly power in DC, then converts it to AC supplying the grid (sometimes with feed-in tariffs), only to reconvert it back to DC at the point of consumption. Do we realize the inefficiency and the cost of this? The electronic engineers, driven by energy efficiency have chosen DC as the standard. Over 80 percent of home and office appliances driven by micro-electronics operate in DC, which combines processing capacity with mobility and miniaturization. Suffice to check the number of chargers, which actually are AC/DC converters that are scattered through our homes to realize the inefficiencies that we tacitly tolerate.
Time has come to rethink the decision on the AC standard that has been made over a century ago. The creation of local DC-grids linked to local power sources that can easily supply power in DC represents a new competitive model with high efficiency reducing energy requirements up to 60 percent without compromising on performance or comfort. A local DC grid also influences health and safety. It reduces the risk of fire and electrocution, cuts wiring, metals and maintenance. The switch to local portfolio of DC power is only a first step, additional adjustments are required including a smarter exploitation of available sources. The first and foremost set of opportunities are embedded in a better management of water.
Home owners and office users will quickly agree: water is key. It always has come as a surprise how little effort building designers make to use the laws of physics to improve the quality of life in general and energy efficiency in particular. A fresh look at water could change that. For example, a thermosyphon functions all year, with hot water rising predictably to the top. Today, residential and office buildings rely on pumps - with increased cost and energy consumption. If on the other hand solar energy, or even just luminescence were used to generate electricity and to heat water, exploiting both sides of photovoltaic panels as provided by the Swedish innovation company Solarus AB, then four to six units are sufficient to provide electricity, hot water and cooling to a family home in Scandinavia. Multifunctional technologies provide multiple benefits, reducing the cost per kWhr.
Whereas the thermosyphon gets water to top of the building, the downward flow of water - predictable with precision of 6 liters per minute - could generate power while adding extra benefits. For example, the flow could power the production of ozone to purify water on site from dissolved oxygen in the water, and could destroy elemental chlorine at the same time. If the water were stored in tanks at 80 or even 90 degrees, then water can be delivered at 38-40 degrees, providing additional DC power through a solid state heat exchange exploiting the 40-50 degrees differential. This power source used to be considered negligible, since the amount of power that could ultimately be fed into the AC grid is trivial.
We can continue the logic of “use what you have to gain multiple benefits” to waste water, and solid waste management. Any building or block in a city hands over its waste to a service provider against a fixed cost per cubic meter or ton. Insights into the biochemical reactions of the slurry from black water and organic solid waste permitted to generate four times more methane gas than previously considered viable. These waste streams, guaranteed as long as people are present, now provides a stable and cheap source of methane. If one combines this smart chemistry provided by Scandinavian Biogas with the vortex technology of AgroPlas from the UK, one has on demand access to local hydrogen to power fuel cells, with solid carbon powder of commercial value as the sole residue. While this will be readily dismissed by the experts in the field since it sounds to good to be true, it is already reality. Better it is competitive, thus it will change the rules of the game.
The biggest challenge we face is that too few building designers and energy experts have been trained to think along these lines. In addition, the few who have this capacity lack access to off-the-shelf tools and equipment to implement this. The few opportunities and options described plus dozen others presented on <www.blueeconomy.de> are therefore understandably dismissed as unviable, futuristic or at least too costly. Time has come to navigate from fantasy to a vision based on science so that these opportunities can soon become mainstream. This requires leadership from a few, and a preparedness to leave our comfort zones. Then we can embrace the shared need to steer business and society towards sustainability - with what we have.