iHOGA is a software for the simulation and optimization of hybrid electric systems based on renewable energies, stand-alone (off-grid) or grid-connected systems.
More info in the user manual (download area).
Optimization is the minimization of total system costs (or maximization of profits) over the system lifetime, transferred or updated to the initial moment of the investment (Net Present Cost, NPC). That is, in general the optimization is economic (mono-objective).
iHOGA software uses advanced models for the components and also for the control strategies, being able to realize simulations of the behavior of each system much more precise than other softwares.
The program also allows multi-objective optimization, where not only the minimization of costs is considered, but also the simultaneous minimization of other variables that the user selects (equivalent CO2 emissions and/or unmet load). Since both objectives (cost and emissions or unmet load) are in many cases contradictory, when the system performs the multi-objective optimization it does not reach a single solution, but provides a wide range of solutions, some with better behavior in terms of emissions or unmet load, others with better behavior in terms of costs. The Human Development Index (HDI) and job creation can also be optimized in multiobjective (with these cases the objective is to maximize).
There is also the possibility of optimizing temporary installations (which are used only for a period of time, with the need to transport, assemble and dismantle them), minimizing the associated cost or weight to be transported.
iHOGA allows the automatic download of NASA’s web of irradiation, wind and temperature data.
The elements that can compose the hybrid system are:
• Photovoltaic panels
• Wind Turbines
• Hydraulic turbine
• Fuel cell
• H2 tank
• Batteries (lead-acid or lithium)
• Battery Charge Controller
• Inverter (DC/AC converter), rectifier (charger, AC/DC converter) or inverter/charger (including inverter, rectifier and controller)
• AC generator (gasoline, diesel …).
Version 2.5 also includes thermoelectric generator (TEG, Seebeck effect).
Although the combination of all of them is possible, in many cases it will be interesting that the hybrid system only includes some of them.
The photovoltaic generator can be connected to the DC bus (by default, DC coupling) or to the AC bus (with its own inverter for AC coupling). Wind turbines can also be defined in AC or DC. The hydrogen components (fuel cell and electrolyzer) can also be connected to the DC bus (by default) or AC (with their respective inverter and rectifier).
iHOGA includes an extensive database of the different components. Economic calculations can be done in any currency.
The load (consumption) of the system can be:
• AC electrical load: electrical appliances that consume electrical energy directly in AC.
• DC electrical load: electrical appliances that consume electrical energy directly in DC.
• Hydrogen load (production of H2 for off-site consumption, for example to power electric vehicles based on fuel cells).
• Water consumption from a supply tank, water that will be previously pumped by an electric pump from a well or river to the tank.
Simulations can be performed in time steps of between 1 and 60 minutes. We can see the screen of the simulation of each combination of components and control strategy considered, and we can save the simulation data in Excel format.
The program also incorporates the possibility of selling electrical power to the AC grid (the remaining power that has not been consumed in the system), to buy the unmet load to the AC grid, as well as to sell the surplus hydrogen produced in the electrolyzer and stored in the tank.
In AC grid connected systems, when renewable sources can not supply all the energy demanded by the load, the supply of the remaining energy can be prioritized by the AC network or by the batteries/generator.
You can simulate installations of renewable energy without load consumption and connected to the AC grid and study their economic viability. The sale to the AC grid can be of all the excess energy (energy that cannot be used by the system) or considering Net Metering scheme (different modalities are available).
The program optimizes both the combination of elements and the system control (which determines when to use one batteries or diesel generator, to what state of charge the batteries must be charged, …).
It can also be considered the case of batteries connected to the AC grid, optimizing the periods of charging (purchase of electricity from the AC grid) and discharge (supply the load consumption through the battery, which can even inject energy into the AC grid to sell it).
iHOGA performs a detailed report of each combination of components considered, in addition to an economic report with the cash flows.
No other hybrid system simulation and optimization software uses advanced optimization algorithms except iHOGA, which uses genetic algorithms. Other programs perform optimization by testing all possible combinations. One problem with this methodology is that if the number of possible combinations is very high, the calculation time increases enormously and becomes unfeasible. In addition, in other software system control strategies are too simple, and no in-depth optimization is possible as in iHOGA. Other advantages of iHOGA are in the models used, more precise than other softwares, in the components as well as in the economic calculations, besides functionalities like the pre-sizing, the optimization of the slope of the photovoltaic panels, the probability analysis, the ageing models of the batteries (Lead-acid or Lithium), the multi-objective optimization, etc.
You can get more info in the User Manual. There is also available a Getting Started guide to learn to use the software (download area).