As Power Network Tycoon has grown, one of the features I knew I wanted to include was renewable energy. Not just because it’s a hot topic in real-world power networks, but because it adds new layers of strategy, infrastructure planning, and challenge for you. I’ve now added wind turbines, solar panels, and battery storage to the game, and getting them up and running on your island involves more than just plopping them down.
Before you can build your first wind or solar installation, you’ll need to do a bit of research. Specifically, you need to unlock the Energy Hub Substation (EHS) and Inverters.
- EHS acts as the central point where renewables connect into your grid. It’s kind of like your renewable power generation connection point.
- Inverters are required to convert the variable DC power from solar and battery systems into usable AC power for the grid.
This approach makes renewables feel earned and adds to the tech progression in a meaningful way as well as providing unlockable content for further into the game.
One of the biggest changes to the game was that now you wouldn’t be able to push a power generator to 110%, as you only had 100% of the power you were generating from the solar or wind at that time. If you went beyond this (without batteries), I needed to introduce power quality issues to the network, which visually means that for some substation’s connected buildings, they would turn off and on which is essentially what the term ‘flicker’ or ‘voltage sag’ is used for in the industry. This meant introducing an additional state the buildings could be in.
Wind power in the game is intermittent with wind generation fluctuating throughout the day, and storms can cause spikes in output. I’ve also added some nice visuals, turbines spin faster or slower depending on the wind speed as well as facing wind direction as it changes. The wind turbines also have a cut-out speed at which they will stop producing electricity if the wind exceeds a very high value (unlikely to occur in the game) which adds a bit of realism.
Solar is predictable but limited. You’ll get a steady supply of power during daylight hours, but output ramps up and down based on the sun’s position. Clouds and overcast weather reduce efficiency, so solar farms are best used with some backup or storage options. Solar efficiency is also reduced if blocked by trees, buildings or rocks and can be increased if they are configured to face the right direction for the sun at that time. Solar also doesn’t work at night (obviously), which introduces natural demand for...batteries!
Battery storage lets you store excess energy generated when renewable generation exceeds demand and can be fed into the grid when generation drops off. They act like a buffer storing power from solar during the day and helping you ride through night-time demand or wind lulls. I added a nice visual on top of them as well so you can see how much energy they have remaining or watch them charge during the day.
One of the biggest differences in how I implemented renewables into the game compared to games without renewables is with inverters, which are a critical part of renewables. With most renewables producing DC power, and buildings using AC power, the inverters are used to both connect renewables but also as a form of DC grid, allowing for expansion over great distances. For performance reasons, I try to limit the number of generators in the game, so I only allow one EHS and want all my renewables to connect to it, which they do via inverters. You can form a string of inverters from the EHS, which itself was challenging to properly detect if a string broke.
Taking inverters a step further, I introduced a new concept to the game, which is grid stability and synchronous generation. This topic is at least partially relevant for events such as the recent Spanish blackout (April 2025) or the Adelaide blackout (September 2016) but a complicated topic.
Power Network Tycoon has two types of inverters, which are either grid-forming or grid-following inverters. If you have solar at home, you almost certainly have a grid-following inverter, that requires you to be connected to the grid to use your solar, however if you pay a bit more and want to be able to be off-the-grid, you can get a grid-forming inverter. These get more complicated as they scale up and it's an area of much research and complicated simulations.
In the game however, a simplified approach is taken where, as the literature [1,2,3] points towards, around 20-30% of the grids generation should be grid-forming or synchronous such as from oil Power Generator assets. So if the player tries to create a fully renewable powered grid with grid-following inverters, they will discover building loads will have power quality issues with lights flicking off and on at night. However they can upgrade their inverters to be grid-forming for a high renewables penetration network, which also relates to an achievement in the game.
Adding renewables isn’t just about clean power, it changes how you build your grid. You need to account for variability, storage, and redundancy in a way that isn’t as urgent with oil based power generators. It forces you to think ahead, balance priorities, and design for resilience.
[1] CSE Article