Discrepancies in simulation and financial analysis results (Neshody ve výsledcích simulace a finanční analýzy)

[jopedy]

Dobrý den, při kontrole výsledků jsem objevil rozdíly v simulaci a ve finanční analýze. Momentálně pracuji v testovací 30ti denní verzi zdarma. 
Pro lepší pochopení vysvětlím na jednom příkladu. Spotřeba celého objektu včetně vlastního zařízení je 8049kWh, z toho pokryto z FVS je 3988 kWh/rok, pokryto ze sítě 4071 kWh/rok. Takže když chci zjistit úsporu za rok, měl bych vynásobit cenu za kWh spotřebou, která je pokrytá z FVS, výsledek je 3988xA, kde A je konstanta. Jenže úspora v cashflow za rok je ale skoro dvojnásobná - 3988xAx2. V čem je problém? Domnívám se, že tyto částky by měly být stejné. Proč tyto sumy nejsou stejné? Samozřejmě pak to má dopad i na výpočet špatné doby amortizace. Budu rád za vysvětlení nebo radu, jak to opravit, aby to počítalo správně, protože pak nevidím důvod, proč bych měl platit peníze za nefunkční software. Dekuji. Pepa

[developer_mh]

Hi jopedy,

here is a translation of your inquiry from deepl.com:

Quote

Hello, while checking the results I found differences in the simulation and in the financial analysis. I am currently working in the free 30 day test version.
For better understanding I will explain with one example. The consumption of the whole building including own equipment is 8049kWh, of which the PVS covered is 3988 kWh/year, the grid covered is 4071 kWh/year. So if I want to find the savings per year, I should multiply the price per kWh by the consumption that is covered from the PVS, the result is 3988xA, where A is a constant. But the savings in cashflow per year is almost double that - 3988xAx2. What is the problem? I believe these amounts should be the same. Why aren't the amounts the same? Of course, then it also impacts the calculation of the wrong amortization period. I would be glad for an explanation or advice on how to fix this so that it calculates correctly, because then I don't see why I should pay money for non-functioning software. Thank you. Pepa

The easiest way would be that you send your project file over to me, here in the forum as private message.

Quote

because then I don't see why I should pay money for non-functioning software

Let us talk about that later when we see if the software was wrong, ok? And even if the software was wrong, nobody urged you to pay for it. Like in the real world, let us not forget how to be friendly to each other.

Martin

[jopedy]

Dobrý den, v příloze zasílám dva projekty.

Nemyslel jsem to nijak zle, ani zde nechci hanit Váš program, jsem začátečník, s programem se učím, nepopírám, že může být chyba na mé straně, pokud je potřeba zadat ještě navíc například nějaká vstupní data, že jsem tak nemusel učinit nebo jsem mohl nějaká data zadat špatně. Jen jsem konstatoval, že pokud by nebylo možné vyřešit můj problém, nebo by problém nebyl na mé straně, pak nebudu mít zájem o placenou plnou verzi programu - bohužel. Navíc nevím, zda bezplatná zkušební verze, kterou nyní využívám, je nějak omezená či nikoliv, což by pak mohl být ten problém, proč to dle mého názoru nepočítá dobře hospodárnost.

Děkuji za ochotu a přezkoumání mých projektů.

FVE RD (8kWp).pvprj FVE OU (4,5kWp).pvprj

[developer_mh]

Hi jopedy,

here is your translated post:

Quote

Hello, I am attaching two projects.

I didn't mean any harm, I don't mean to denigrate your program either, I'm a beginner, I'm learning with the program, I don't deny that there can be a mistake on my side, if I need to enter some input data in addition, for example, that I didn't have to do so or I may have entered some data wrong. I was just stating that if my problem could not be solved, or the problem was not on my side, then I would not be interested in the paid full version of the program - unfortunately. Additionally, I don't know if the free trial version I'm currently using is somehow limited or not, which could then be the problem as to why it doesn't calculate well for economy in my opinion.

Thank you for your willingness and review of my projects

No worries, sometimes I find it hard to get the tone right when I only see written text. I just found the phrasing a bit harsh that you called our software a non-functioning software before even having clarified if it is working correctly or not. But let's get forget about that and go on with the actual question.

First thing that I saw was that the price per kWh in the net metering tariff should be 7 ct instead of 7 €, I guess:

 

Then, if you have a net metering tariff, the amount of PV energy that is directly used by your consumers actually does not matter. Net metering just balances your PV production (per year or per month depending on the tariff) against your consumption. You have a annual consumption of 8059 kWh and a PV production of 8158 kWh. That means you have a "cumulative total energy generation" of approx. 100 kWh (the last point in the diagram of December). You generate more than you consume, so according to the tariff that you entered, you do not have to pay for the consumed energy. This saves you 8059 kWh * 0,07 €/kWh = 564,13 € (or actually 8000 kWh * 0,07 €/kWh = 560 €, because 59 kWh of the consumption come from the PV inverters that you would not have without a PV system.

 

Calculated without inflation rates or interest on capital.

 

Best regards,

Martin

[jopedy]

Dobrý den, Martine, 

děkuji za zprávu.

Cena je uvedena v jiné měně - v českých korunách a ne v eurech.

Rozumím Vašemu vysvětlení, které by dle mého názoru bylo relevantní pokud by však soběstačnost FV výroby byla ze sta procent, což ale dle simulací není a proto to pak nemusí vycházet tak, jak by mělo a nevím, jak to ve vstupních datech upravit nebo ovlivnit.

V tomto konkrétním posuzovaném příkladě to shrnu: zadaná spotřeba objektu je 8000kWh za rok + 59kWh spotřeba vlastní FVE neboli střídače, dále vyrobená energie ze slunce je 8158kWh, soběstačnost FVE je však necelých 50% , to znamená dle výpočtů programu, že pokrytí energie celkové spotřeby daného objektu je pouze 3988kWh. Zbytek potřebné roční energie (4071kWh) je pak dodáno ze sítě od dodavatele energie. Přebytky ve výpočtech nechci zohledňovat, neboť jsou v našich podmínkách zanedbatelné a s nástupem komoditní energetiky to ještě může být zcela jinak, takže mi jde o akorát o ekonomické propočty z energie vyrobené ze slunce, která pokryje spotřebu daného objektu dle výpočtu. Takto mi to pak nevychází - 7 českých korun* 3988kWh je jiná suma, než tak která vyjde ve výpočtech hospodárnosti. Snad to bylo dostatečně srozumitelné. Samozřejme nemusím brát zřetel na ekonomické výpočty, ale rád bych využil všechny a kompletní výpočty programu. 

Děkuji za ochotu a Vaši radu.

[developer_mh]

Hi jopedy,

here is your text translated to English by deepl.com:

Quote

Hello, Martin,

thank you for your message.

The price is quoted in a different currency - Czech crowns, not euros.

I understand your explanation, which in my opinion would be relevant if however the self-sufficiency of PV production was one hundred percent, which according to the simulations it is not and therefore it may not come out as it should and I don't know how to adjust or influence it in the input data.

In this particular example under consideration I will summarise it: the specified consumption of the building is 8000kWh per year + 59kWh consumption of the PV or inverter itself, furthermore the energy produced from the sun is 8158kWh, however the self-sufficiency of the PV is less than 50% , this means according to the calculations of the program that the energy coverage of the total consumption of the building is only 3988kWh. The rest of the required annual energy (4071kWh) is then supplied from the grid by the energy supplier. I don't want to take the surplus into account in the calculations, because it is negligible in our conditions and with the advent of commodity energy it may still be completely different, so I am only concerned with the economic calculations of the energy produced from the sun, which will cover the consumption of the building according to the calculation. That's not how it works out for me then - 7 Czech crowns* 3988kWh is a different amount than what comes out in the economic calculations. I hope that was clear enough. Of course I don't have to take into account the economic calculations, but I would like to use all and complete calculations of the program.

Thank you for your willingness and your advice.

I do not know the Czech tariffs system in detail, but from what you explain here, it is not a net metering tariff then. If you receive amount x for energy that you export into the grid, and you have to pay amount y for energy that you buy from the grid, then the economic scheme that you have to choose is "Surplus feed-in". Then you can define the two tariffs separately and everything will be calculated as you described it:

Hope that helps, kind regards,

Martin