Mana Energy

Edda is an immensely magical land, with your typical spells and grand magical artifacts, but also with technology and scientific advancements using the power of Magic itself. But the question is, how do you use Mana as a power source, and how do you use it effectively?
The answer to that is rather simple and began with the work of Druids and ancient Witches. Essentially, specific runes are forged, typically in the native language of the caster or a specific language such as Druidic or even Thieves Cant depending on the caster, and then a circle is placed around it that specifically pulls in Mana from a nearby Leyline. For the best performance, such runes are placed directly on top of a Leyline, and you'll see older establishments that use such technology are built upon the leylines.
However, in the modern-day as expansion continues and not every location is Leyline Viable, industrial minds have found that placing a runic circle on the center points or crossroads of Leylines to *expend* energy, and then placing piping systems made with metal, or cords of conductive materials, and then placing those on buildings can allow the *pull* energy circles to do their job as efficiently as they would if the Leyline was directly underneath them.
A problem does arise when using this method, however. As mana travels from its Leyline it can curate impurities, and especially when it's used it takes on the waste of the spell or arcane task performed. When it comes to Spellcasting, this isn't an issue, as the caster's own magic does the work of purifying the energy expended, which is why even a failed spell takes the energy of the caster. Enchantment of items usually performs the cleaning by limiting the usage, via charges, or by merely placing a flat effect on a weapon.
But for magical energy, there needs to be natural milling of the energy in order to keep it clean, otherwise, it could malfunction or misfire, which could lead to disastrous results. This has led to many different places developing natural energy systems in order to filter the magic through Mana Purification Facilities. For example, while Theogany uses a lot of Wind-Based milling, but also uses their advanced sewer system to purify the mana along with the water.
Some places do it wildly differently. The starkest case would be Alicein which manages to connect Mana together via natural means, using vines, branches, shells, or other such items, which reduces the number of impurities garnered via the transfer, and since it's a natural, living thing most of the time, the natural filtration of the being, such as photosynthesis, goes a long way to cleansing the mana within.

Utility

The Runic usage of Mana Energy was first discovered the same way many technologies are discovered; because someone wanted an extra bit of convenience and had the knowledge to do it. No one knows exactly who the first person was, but someone ages ago, before Dark Sun split magic into its disparate schools, was facing quite the frigid night. This individual, a druid most likely, had been studying Witches technique of storing magic into certain objects and attempted to store a spell within a specific runic circle rather than an item, and was surprised to find that it worked, as they used the circle to maintain a Create Bonfire spell.
Rumors spread of this technique, and eventually, it was being studied and examined in magical institutions all over Edda. Even after Dark Sun occurred, and magic was fractured, it was relatively easy to adjust the necessary circles and runes for their necessary magical equivalents.
Filtration systems were first utilized after a 'polluted' energy line almost caused a forest fire in Hippolyta. Institutions in Magnum Opus and Atalanta were the first to develop newer technologies, and with a blueprint for cycling energy through Arcane Crystals, ones that could be cleansed with personal mana or eliminated safely, it became the job of individual countries to find out how to best integrate the systems with their natural infrastructure.

Manufacturing

To create a Mana Energy system, you first need a Rune. This rune, or occasionally series of runes, will be what describes the purpose of the energy. It can be as simple as "Chill" or as complex as "pulse energy every 15 Seconds" depending. All that is required is that the runes are written either with the caster's internal Mana or with Mana-Infused Ink so that the absorbed energy has something to cling to. The act of writing out the request is an Arcane Scribe technique, as to make simple words arcane commands.
Next, one must create a Magic Circle around the runes. Not only does this create a pathway for the Mana to travel through, but it also denotes the runes as the purpose, rather than merely a string of words. The circle must be designed in order to draw mana inward to the runes in the center of the circle from the Leyline, but other than that can be drawn however the caster deems fit.
Filtration systems are a bit more complicated, but let's use Wind-Powered Filtration as an example. A facility is set up on an active Leyline, usually a clump of crossing Leylines, but a large one regardless, and absorption circles are set up, but instead of going into a Rune, they go into two empty Arcane Crystals, adept at absorbing mana energy, which is powered not by the leyline itself but instead by the naturally produced energy of the Windmill. As the use of Mana Energy creates impurities that flow back to the Leyline, the absorption circles are tuned to absorb those impurities into the first crystal, which then stores the impurities within itself as the rest of the mana flows into the second empty crystal, keyed to store the clean energy. Once the Pure crystal has been filled, the mana is then carefully released back into the main Leyline, as to not create a spike in energy. It takes more time to fill the Impure crystal, which is then replaced with another while it's cleansed.
The cleansing process for Impure crystals is rather simple, a professional magic-user, typically skilled at Transmutation Magic, changes the pure impure energy into something tangible, most commonly Carbon-Dioxide, as it's simple for plants to process that in a natural way. Even if one isn't a transmutation based wizard, Magic Scrolls are available for use and are generally inexpensive to create, although as it has less of an individual touch, there is a wider margin of error.

Inventor(s)

There's no one individual that can be called the inventor for Mana Energy or filtration, as it's a process that exists all over Edda indiscriminately, and many people came up with similar situations that are equally feasible. There can be inventors for individual processes, but there would be far too many variations to list.

Access & Availability

Mana Energy is available anywhere there is a powerful Leyline, although the weaker branches can make the amount available rather low. Filtration systems, however, are mostly present in large cities, although smaller cities and villages will typically have at least 1 source of filtration system for the town's local Leyline, although there will typically be less need for Mana Energy systems in those smaller locations.

Complexity

Mana Energy isn't difficult to use, as long as one has a rudimentary idea of how Mana flows and how to set up the runes. However, for more advanced systems, along with just general public safety, it is typically left to experts. Many Wizards and Druids are responsible for this task, along with some Sorcerers and the rare Mana Hacker.
Filtration systems are much more advanced, and typically require individuals trained in the specific industry that is used.

Discovery

Mana Energy has existed since Mana itself did, although the current runic system did have to be reinvented following the tragedy of Dark Sun and the division of Magical Energy. The systems of filtration for Mana Energy, however, are relatively modern, dating back about 100 years at the earliest and continuing to be refined.