A standalone grid is just the wording for an autarky power supply system where supply and demand are matched vice versa within a constant process.
Advantages:
- providing a reliable power supply without daily blackouts
- providing a sufficient power supply system
- providing an affordable energy supply
- providing additionally to the electrical power CHP generated “waste heat”
- taking advantage of your existing equipment
Disadvantages
- A standalone system always has to provide the necessary power to supply peak demand levels, therefore the installation capacity is far above the average needed power (see gridparallel)
- PV and wind power plants need a backup to store and release the generated power. This is only economical for smaller applications
- controlling and steering has to take place constantly by matching supply and demand demanding additional infrastructure
Designing a power supply system for you is based on three main pillars:
- identifying your actual demand profile
- identifying your energy consumption which can be covered “for free" due to CHP characteristics of gas generators
- identifying consumers which can be shifted timewise to reduce peak demand and/or to increase low demand levels
All these parameters have a significant influence on the size and the components of your standalone system:
ad 01: the peak demand defines the total electrical capacity you have to install the low demand defines the size of the smallest gas generatorsharp jumps and drops in demand define the size of the Central Load Stabilizer (CLS)
Therefore to analyze the Status Quo today is the key for proper planning.
ad 02: gas generators provide due to their CHP characteristics not just electricity, but as well lots of “thermal energy” in form of hot water.
Do you heat your water with a diesel burner or with electricity?
ad 03: are there operations within your facility which can take place during low demand instead of peak demand?
Do you run a laundry which could work as well during night?
Are there any “movable” electrical consumers?
As your system always matches supply and demand you generators change their power output continuously between ranges of about 50 to 80% of their installed capacity. When for example they approach 80%, the next generator gets started, when the power goes down to 50%, a generator gets shut down.
As gas generators have their best efficiency (of about 43%) at 100% of their capacity, within a standalone system the efficiency normally ranges at “only” about 40%.
