The following new features have been included in version 3.4 (updated 2023, January 22):

–  Added the possibility to inject power to the AC grid from the fossil fuel generator (AC generator) in NPV maximizing systems (in generating systems which sell electricity to the grid).
– Added C-rate for grid-connected battery charge / discharge.

– Added the possibility to consider wake effect in wind turbines.
– Added the availability (hourly and monthly) for electrolyzer and for fuel cell.
– Added variable efficiency for the water pump (for PHS and for water supply).
– Choose power limit for priority to use surplus Energy in pump or in batteries
– In Excel file obtained in simulation, added column of efficiency of turbine, efficiency of pump and efficiency of electrolyzer (% of HHV).
– Improved visual effects in graphs, adding checkbox for the different series.
– In load window the graph includes the water load (in energy pumped) and shows the total average daily energy for each month.
– In iHOGA high power projects and in MHOGA, added the possibility to connect PV generator and wind turbines to the DC bus.
– Extended download irradiation/wind/temperature hourly data from PVGIS for all around the world.
– Changed maximum current in li-ion batteries databases to C/2.
– Corrected problem with full equivalent cycles model of li-ion batteries when including calendar ageing for cases of very low discharge current.
– Corrected bugs in some cases with PHS storage.
– Corrected bugs when showing unmet load in multi-objective optimization.
– Fixed minor bugs.

The following new features have been included in version 3.3 (2022, september 29th):

– Added a new li-ion LiFePo4 battery degradation model (Naumann et al., 2020).
– MHOGA: In maximization of the net present value (NPV) projects, added the constraint of the minimum renewable capacity factor (sold energy divided by peak power of the renewables multiplied by 8760 h).
– MHOGA: In maximization of the net present value (NPV) projects, added the constraint of the maximum land use.
– In maximization of the net present value (NPV) projects, added the the result of the renewable capacity factor (sold energy divided by peak power of the renewables multiplied by 8760 h).
– MHOGA: In maximization of the net present value (NPV) projects, added the result of the land use.
– In maximization of the net present value (NPV) projects, when a solution does not meet all the constraints, it is assigned an NPV of –infinite (before it was assigned 0).
– Added the number of cycles to failure for 100% DOD of the batteries.
– Fixed bugs

The following new features have been included in version 3.2:

• Added calculation of direct irradiance when downloading data from databases.
• Added graph of direct irradiance.
• Added possibility to consider Concentrating PV (CPV) modules or generators.
• Corrected bugs when downloading NASA hourly data.
• Corrected bugs of multi-objective optimization (when using unmet load as objective).
• Corrected bug when calculating back surface irradiation if solar tracking (one or two axis) was selected.
• Corrected minor bugs.

The following new features have been included in version 3.1:

• Added the possibility to use bifacial PV modules.
• Improved reports
• Improved the visualization of the application, adapting to different screen sizes and DPI.
• Added visual themes.
• Fixed minor bugs.

The following new features have been included in version 3.0:

• Added the choice between low power projects or high power projects when creating or opening a project.
• Added multiperiod simulation and optimization: iHOGA can consider the increase in load and the decrease of electricity production from the renewable sources during the years of the system lifetime, simulating the real performance of the system during all its lifetime (20-30 years usually) and calculating the real costs and incomes, obtaining the real net present cost (NPC) or net present value (NPV). It can also consider variable inflation in electricity price during the years and different irradiation and wind speed for each year.
• Added Pumped Hydro Storage (PMH).
• Added the optimization (maximization) of the net present value (NPV) for generating systems (grid-connected generators, with or without storage), calculating the internal rate of return (IRR). Also possibility to optimize minimizing the levelized cost of energy (LCOE) in generating systems (sum of present costs, not incomes, during the lifetime, divided by total energy injected in the grid).
• Before, LCOE was calculated as the total present value of all costs divided by the total energy consumption during the lifetime (or total energy injected to the grid, in grid-connected generators). Now it can be calculated as before or including the real discount rate in the energy.
• Added more options for the control of the storage in grid-connected generators.
• Added the pumped hydro storage (reversible pump turbine or pump and turbine) with control strategies similar to the grid-connected batteries.
• Added the optimization of the contracted power in grid-connected systems.
• Added the contracted power for up to 6 hourly periods in grid-connected systems.
• Added the possibility to register the maximum power demand, usually the average of 15 minutes, reached during the billing period (this average time may vary depending on the country, and it is defined by the user). If that value is higher than the contracted power, the customer will pay a penalty on the electricity bill.
• The wind turbine power curve is now in 1 m/s steps for all the wind speed range.
• Added the cycle life (number of cycles) dependence on temperature, to be used in full equivalent cycles or in Rainflow battery lifetime models.
• In li-ion batteries, added the possibility to consider calendar ageing model together with full equivalent cycles or rainflow cycle ageing models.
• Added the available battery capacity dependence on temperature for each time step.
• Added a minimum stand-by consumption of the electrolyzer, in percentage of its nominal power, consumed during all the time except when it is running.
• The report can be exported to a .rtf file (which can be open by Microsoft Word or other text processor).
• Fixed minor bugs.

The following new features have been included in version 2.5:

• Added the possibility that PV generator can be divided in two zones at different slope and azimuth.
• Added thermoelectric generator (TEG, Seebeck effect).
• Added the option to download hourly data of a whole year (irradiation, temperature and wind speed) from Renewable Ninja (https://www.renewables.ninja/) or from PVGIS (https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html).
• Improved hourly and minutes irradiance calculation.
• Changed security factor to efficiency in PV.

The following new features have been included in version 2.4:

• Added hourly availability of the AC grid (every hour of the year the AC grid can be defined as available or unavailable). This novelty is useful for simulating systems connected to weak AC grids, with frequent blackouts, as occurs in certain areas of certain developing countries.
• In previous versions unmet load (energy not served) was always defined as the demand that can not be covered by the autonomous system (composed of renewable sources, batteries, AC generator, etc.), not considering the AC network. In this version it is possible to define the unmet load as the demand that can not be covered neither by the autonomous system nor by the AC grid, that is to say, the energy demanded by the loads that can not be covered in any way.
• In the previous versions the energy that could not be covered with renewable sources was covered primarily with the batteries / AC generator / fuel cell, and if there was still unmet energy, it was covered with the AC network (if it was available and have activated the purchase of electricity to the AC grid). In this version it is possible to choose that the energy that is not covered with renewable sources is covered as a priority with the AC grid and, if the AC grid is not available or if it can not cover all the demand, try to cover energy not served with batteries / AC generator / fuel cell.
• DC bus voltage can depend on battery bank SOC.
• Corrected the error that when choosing solar tracking in one or two axes did not appear such tracking in the report.
• Fixed minor bugs.

Projects created by iHOGA version 2.3 can be open by iHOGA version 2.4.

The following new features were included in version 2.3:

• Checking the date on the Internet is done more efficiently.
• Bugs fixed.
• Synthetic generation of irradiation, wind and consumption in 1 minute intervals.
• Simulation time steps from 1 minute to 1 hour.
• Unlimited number of AC generators (diesel, gasoline …) are allowed in parallel. The recommended number is obtained by the pre-sizing button.
• Added the possibility of including lithium batteries, with three life models (in addition to equivalent cycles and cycle count): two models for LiFePO4 batteries and one for LiCoO2 batteries.
• Updated databases including lithium batteries.
• Added management of the charge/discharge of batteries in the case of systems with batteries connected to the AC grid, by fixed limits or by optimization of 2 or 3 variables for charging from the AC grid /discharging. You can set hours at which the batteries are available for charging from the AC grid or discharging. You can also set hours at which the charge from the AC grid or the discharge is forced.
• Modeled the increase in aging and O&M cost of AC generator when operating out of its optimal range.
• If the photovoltaic generator is connected to the AC bus via its own inverter (AC coupling), the number of PV panels in serial is indicated by the user.
• Possibility of overloading in inverter and AC generator in simulations with time steps less than 1 h.
• Added stopping criterion in probability analysis (Monte Carlo).
• Added probability analysis of the variation of interest of the price of the fuel of the AC generator.
• Added correlation between input variables for the probability analysis.
• Added the optimization of temporary (removable) installations with a duration of less than one year, in cost or weight.
• The Human Development Index (HDI) can be modeled considering the use of part of the excess energy.
• The job creation of photovoltaic and wind power can be modeled dependent on the installed power.
• At the end of the study period, the residual value of the system components can be considered or not.
• Synthetic generation of temperature hourly data can be performed using the model of Erbs et al., 1983.
• Warn if you create a project with the same name as an existing project.
• Warn if you save a file with the same name as an existing file.
• You can save any project as a default project