Articolul Hello world! apare prima dată în CamperVan Fest Romania.

Cea mai des pusa intrebare pe grupurile de campere sau rulote suna cam asa: „Daca pun un panou de x watts si o baterie de y amperi, imi ajunge un weekend?”

Si eu vin si intreb… ajunge ca sa ce? Vrei sa tii doua telefoane la incarcat si o lumina sau vrei sa incarci biciclete electrice, sa te uiti la televizor si sa sudezi? Orice sistem offgrid sau offcamping trebuie gandit incepand de la consumatori si timp de utilizare, niciodata de la resurse. 

Calculul nu e greu, dar sunt cateva lucruri de luat in considerare: cat consuma fiecare aparat? In principiu scrie pe ele, majoritatea fiind pe 12V, dar vei avea consumul exprimat in amperi sau watt ora. Astfel, daca pe frigider scrie 3 amperi, inmultesti 3 amperi cu 12 volti ca sa afli cati watts consuma, adica 36wh. Adica, pentru functionarea pe 24 de ore, ajungi la 24 de ore ori 36wh, 864wh pe zi. Astfel, pentru a tine un frigider 2 zile de weekend, ai nevoie de 1,7kwh energie sau putin peste 140 amperi ora.

Clar, nu toate echipamentele merg constant. Daca ai o banda de led care e folosita doar 4 ore noaptea si consuma un amper ora, sau 12 wh, inseamna 4 ore ori 1 amper ori 2 zile ori 12 volti, 96wh sau 8 amperi ora, in functie de cum vrei sa exprimi treaba. Dar, de regula, trebuie sa le iei pe toate si sa faci un calcul realist si in nici un caz unul optimist, la modul „lasa ca nu consum atat”. De obicei consumi, si uneori chiar mai mult, si nu e nimic mai nasol decat sa ramai fara curent in concediu.

Acum, ai aproximat pentru frigider, lumini, blender, invertor, televizor, telefoane, pompa de apa si tot ce mai exista prin camper si vei folosi si sa presupunem pentru usurinta ca ne-au rezultat 2500w consumati in 2 zile, ipotetic. Trecand la pasul urmator, hai sa vedem de unde luam curent si cum il punem inapoi. O sa fac un alt episod despre diferitele tipuri de baterii si diferentele dintre ele, dar pentru acest caz, sa presupunem ca lucram cu o varianta ieftine de baterii cu gel, cea mai ieftina posibil. Bateriile cu gel pot fi descarcate pana la 50% din capacitatea lor, deci daca am avea o baterie de 100Ah sau 1280wh, real poti descarca din ea jumatate deci ai 50Ah utili sau 640wh. Daca depasesti o data nu e chiar o drama, insa descarcari repetate sub acest procent vor duce la deteriorarea prematura a bateriilor. Deci, daca vreau sa am energie pentru tot weekendul, as avea nevoie de aproximativ 400Ah sau 5120wh din care sa trag energie constant. Dar mai avem aspectul de reincarcare.

Iar aici intervine panoul. Sunt multe de povestit despre panouri si voi dezbate si partea asta separat dar, ca sa tinem lucrurile simple, o sa luam ca referinta un panou de 300w standard de ferma. Cu o medie de 3-6 ore de productie reala, din experienta proprie acest panou incarca undeva intre 1000 si 1500wh intr-o zi. Sigur, poate varia daca sunt nori, daca e prea cald, daca e panoul curat sau sub un unghi favorabil. Dar daca am lua o medie anuala, as zice 1280wh, ca sa fie si matematica usor de facut. Deci, intr-o zi buna, un panou de 300w poate produce suficient de mult incat sa compenseze pentru ce consumi. In varianta cea mai economica deci, pentru un setup super elementar de weekend, ai avea nevoie de un panou de 300w, 2 baterii de 100Ah sau 1280wh fiecare, astfel incat sa ajungi aproape de 50% cu consumul si un controller solar MPPT.

Exemplul este de rudimentar pentru a prezenta metoda de calcul. In principiu, intr-un sistem mai bun vei avea si control bluetooth de exemplu, pentru a vedea ce consumi, cu cat incarci si cate ore aproximativ poate functiona sistemul tau in regimul actual. Cum am tot povestit, noi in Sprinterul nostru 4×4 avem 320Ah de litiu de la Victron, un Smart Solar 100/30 cu bluetooth si un singur panou de 300w. In general, daca il tinem curat, acesta ne asigura curent fara mari drame pe toata perioada verii. Desigur, aici intervine si bancul de baterii pe litiu si restul componentelor, dar asta-i o poveste pentru alt episod.

Hai sa recapitulam cum gandim un sistem pentru rulota sau autorulota, deci: Pasul 1, vedem ce consumatori avem. Pasul 2, estimam cat timp stau acesti consumatori porniti. Pasul 3, calculam cam cat ar trebui sa fie un banc de baterii care ne tine sistemul fara incarcare. Pasul 4, vedem cate panouri solare si de ce fel putem pune pentru a compensa consumul. Pasul 5, punem totul pe hartie si vedem ce rezulta. In final, hai sa va dau si varianta cea mai des intalnita si care functioneaza pentru o buna parte din cazuri: un panou de 300w sau mai mare daca puteti gasi, un MPPT dimensionat corect cum e un Victron Smart Solar 100/30 si o baterie pe gel de 220Ah, tot de la Victron Energy. Acesta a fost primul meu setup din sprinter si m-am descurcat foarte ok cu el 2 veri. 

In articolele viitoare o sa povestim despre tipuri de panouri dar si despre tipuri de acumulatori. Sunt multe de povestit asa ca fiecare va avea articolul sau dedicat. Asa ca daca vreti sa fie cat de cat clar cum se construieste un sistem fotovoltaic de camper si in ce merita sa investiti cand vine vorba de componente, urmariti blogul si inscrieti-va la newsletter.

Articolul Cum dimensionezi un sistem fotovoltaic? apare prima dată în CamperVan Fest Romania.

The most frequently asked question on camper or caravan groups goes something like this: „If I put in an x watt panel and a y amp battery, will that be enough for a weekend?”

And I come and ask… enough to what? Do you want to keep two phones charged and a light or do you want to charge electric bikes, watch TV and sweat? Any offgrid or offcamping system must be thought from the consumers and time of use, never from the resources.

The calculation is not difficult, but there are a few things to consider: how much does each appliance consume? Basically it says on them, most of them are 12V, but you will have the consumption expressed in amps or watt hours. So, if the fridge says 3 amps, multiply 3 amps by 12 volts to find out how many watts it consumes, i.e. 36wh. That is, for 24-hour operation, you get 24 hours times 36wh, 864wh per day. So to keep a fridge going for 2 weekend days, you need 1.7kwh of energy or just over 140 amp hours.

Clearly, not all equipment works consistently. If you have an LED strip that is only used for 4 hours at night and consumes 1 amp hour, or 12 wh, that’s 4 hours times 1 amp times 2 days times 12 volts, 96wh or 8 amp hours, depending on how you want to put it. But, as a rule, you have to take them all and make a realistic calculation and in no case an optimistic one, in the „let me not consume so much” way. You usually consume, and sometimes even more, and there’s nothing worse than running out of power on holiday.

Now, you’ve approximated for fridge, lights, blender, inverter, TV, phones, water pump and everything else around the camper and you’ll use and let’s assume for ease that we got 2500w consumed in 2 days, hypothetically. Moving on to the next step, let’s see where we get the power from and how we put it back. I’ll do another episode on the different types of batteries and the differences between them, but for this case, let’s assume we’re working with a cheap gel battery variant, the cheapest possible. Gel batteries can be discharged up to 50% of their capacity, so if you have a 100Ah or 1280wh battery, you can actually discharge half of it so you have 50Ah usable or 640wh. If you go over once it’s not really a drama, but repeated discharges below this percentage will lead to premature battery damage. So, if I want to have power for the whole weekend, I would need about 400Ah or 5120wh from which to draw constant power. But there is also the aspect of reloading.

And this is where the panel comes in. There’s a lot to talk about panels and I’ll discuss that part separately but, to keep things simple, we’ll take a standard 300w farm panel as a reference. With an average of 3-6 hours of actual production, in my experience this panel charges somewhere between 1000 and 1500wh in a day. Sure, it can vary if there are clouds, if it’s too hot, if the panel is clear or at a favorable angle. But if we were to take an annual average, I’d say 1280wh, for easy math. So, on a good day, a 300w panel can produce enough to compensate for what you consume. In the cheapest version then, for a super basic weekend setup, you would need a 300w panel, 2 batteries of 100Ah or 1280wh each, so you get close to 50% consumption and a MPPT solar controller.

The example is rudimentary to present the calculation method. In principle, in a better system you will also have bluetooth control for example, to see what you consume, how much you charge and approximately how many hours your system can run in its current mode. As we’ve been talking about, in our Sprinter 4×4 we have 320Ah lithium from Victron, a Smart Solar 100/30 with bluetooth and a single 300w panel. In general, if we keep it clean, it will provide us with power without much drama throughout the summer. Of course, this is where the lithium battery bank and the rest of the components come in, but that’s a story for another episode.

So let’s recap how we think about a system for a caravan or motorhome: Step 1, we see what consumers we have. Step 2, we estimate how long these consumers stay on. Step 3, we calculate about how much a battery bank should be to hold our system without charging. Step 4, we see how many solar panels and what kind we can put to compensate for consumption. Step 5, we put everything on paper and see what results. Finally, let me give you the most common option that works for a good part of the cases: a 300w panel or larger if you can find it, a correctly sized MPPT such as a Victron Smart Solar 100/30 and a 220Ah gel battery, also from Victron Energy. This was my first sprinter setup and I did very ok with it 2 summers.

In future articles we will talk about types of panels and types of batteries. There is a lot to tell so each one will have its own dedicated article. So if you want to be as clear as possible how to build a PV camper system and what is worth investing in when it comes to components, follow the blog and sign up for the newsletter.

Articolul How do you size a photovoltaic system? apare prima dată în CamperVan Fest Romania.

Daca vrei sa stai offgrid, intr-un fel sau altul trebuie sa ai de undeva curent pe care sa-l poti consuma. Ca vrei o lumina ca sa citesti, priza pentru laptop sau sa-ti incarci telefonul, energia aia trebuie sa vina de undeva. Iar in acest articol vreau sa vedem de unde vine energia, cum se stocheaza si cum se consuma din diverse tipuri de baterii. Sa le trecem in revista in prima faza si sa vedem cu ce ramanem real: 

Avem bateriile normale de masina cu plumb, apoi avem deep cycle gel, bagam in lista si litiu-ion desi meh si litiu fier polimer sau lifepo4. Bateria pe plumb pica, e gandita pentru tractiune, adica sa-ti dea curent sa pornesti masina. Nu este gandita pentru consum constant si se va deteriora repede. Mai scapam si de Litiu-ion pentru ca nu-s chiar uzuale si sunt destul de periculoase, uneori avand niste reactii exoterme destul de interesante si violente. Ramanem pe masa cu deep cycle si lifepo4, caruia-i vom zice litiu de acum pentru usurinta.

Bateriile le vom compara dupa cateva criterii: pret de achizitie, greutate, durata de viata, numar de cicluri si DoD sau depth of discharge, productie totala. Sigur, putem merge mult mai in detaliu dar am zis sa ne concentram doar pe cele mai importante chestii. As face o mentiune aici, ca vom vorbi de baterii cu litiu de serie si nu variante de celule cu balansare aftermarket sau solutii DIY. Sigur, se pot face, dar e o bataie de cap si 3 din 5 oameni pe care ii cunosc si care si-au facut au probleme cu ele. Astfel, pentru a pastra echilibrul, luam 2 baterii de la acelasi producator si le comparam. 

O sa alegem un Victron AGM de 100Ah si un Victron LiFePO4 de 100Ah de asemenea, adica 1280Wh sau 1,28kWh. Sigur, primul lucru pe care il vom observa este costul de achizitie foarte, foarte diferit. Pe site-ul celor de la Darcom Energy, varianta AGM este 1800 RON iar cea cu litiu 7100 RON si de aici se cam separa treburile rapid. Urmatoarea diferenta usor de intuit are de-a face cu greutatea si gasesc ca este un aspect extrem de important pentru un camper. In cazul variantei de 100Ah, litiu este sub jumatate din greutatea AGM-ului. Pe masura ce cresc capacitatile, diferenta ajunge sa fie 1 la 3 sau chiar 1 la 4, bateriile deep cycle de obicei fiind destul de grele. O sa revenim la problema greutatii in raport cu Depth of Discharge, pentru ca e un aspect foarte important. Deci am stabilit pana acum ca litiu e mai usor si mai scump. Astea le numim observatii empirice elementare.

Trecand mai departe, ajungem la durata de viata ca numar de cicluri, care este influentata de acest Depth of Discharge. Un acumulator deep cycle are un DoD optim de 50%. Asta inseamna ca din 100Ah din bateria noastra etalon, putem folosi 50Ah inainte sa inceapa sa se degradeze destul de serios. In Data sheet-ul de pe site-ul Victron, ne informeaza ca la 50% discharge noi avem 600 de cicluri de baterie. Bun. Deci in viata acestei baterii, noi putem folosi de 600 de ori cate 50Ah. Ca sa pastram un echilibru, ramanem tot la 50% DoD si ne uitam ce scrie in Data Sheet-ul pentru litiu. Pentru aceleasi specificatii, la varianta 2022 a bateriilor, cu un DoD similar, aceeasi baterie suporta 5000 de cicluri de incarcare, deci de 8,3 ori mai multe cicluri. Insa aceasta nu e cea mai relevanta trasatura a acestor baterii, sau in general a litiului, ci faptul ca suporta un DoD de 80%, unde au 2500 de cicluri. Deci, spre deosebire de o deep cycle de unde poti trage 50Ah dintr-o baterie de 100Ah, aici poti trage 80Ah dintr-o baterie de aceeasi capacitate. Durata de viata normala a unei baterii cu gel este 5-7 ani, pe cand durata de viata a unei baterii cu litiu este de 15-20 de ani, deci adaugam si asta la lista de diferente notabile.

Si aici revenim la greutate, pentru ca noi initial am calculat greutatea la achizitie, cea care defineste cat platesti la FAN Courier ca sa iti ajunga bateria acasa. Insa acum, cu noile date, calculam in functie de energia disponibila. Daca din bateria cu litiu putem scoate 80Ah si are 15 kg, pentru a scoate aceeasi energie din gel avem nevoie de un acumulator de 160Ah care cantareste 47 kg. Si iata ca am mai adaugat o bila neagra la gel, sau alba la litiu, sau cum vrei sa ii zicem.

Cu toate aceste informatii, mergem iar la costuri si sunt doua aspecte importante: pretul pe kWh la achizitie si pretul pe kWh pe toata durata de viata a bateriei. Clar, la achizitie gelul castiga detasat cu 1400 RON per kWh pe cand litiu sare de 5500 RON per kWh. Revenim un pic la numarul de cicluri si DoD ca sa calculam pretul pe kWh pe viata. Luam strict DoD 50%, si pentru gel vom avea 50Ah adica 0,6kWh x 600 cicluri deci 360kWh pe toata durata vietii. Pentru litiu avem 50Ah, deci aceiasi 0,6kWh x 5000 cicluri deci 3000kWh pe toata durata vietii acumulatorului nostru. Impartim la pretul de achizitie si ne rezulta ca gelul are un cost de 5 lei pe kWh iar litiu de 2,36 lei pe kWh, deci mai putin de jumatate.

Recapitulam: cost de achizitie, 1-0 pentru gel. greutate 1-1, recupereaza litiu, DoD 2-1 pentru litiu. Cicluri de viata 3-1 pentru litiu. Pret per kWh achizitie, punct pentru gel, deci 3-2. In final Pret per kWh pe perioada de functionare, 4-2 pentru litiu. Si mai era diferenta de durata de viata de la … hai sa zic 7 ani la gel, ca ma simt darnic, si 15-20 de ani la litiu. Deci 5-2 si s-a incheiat meciul. Sunt de acord ca aceasta varianta are un pret de achizitie mai mare, insa am demonstrat impreuna ca, de fapt, iesi mai bine la orice capitol relevant. De multa vreme ma tin sa pun pe hartie calculele astea. Sunt sigur ca pe ici pe colo m-am exprimat gresit, am zis watts in loc de watts ora sau te miri ce. Sunt sigur ca vom afla impreuna unde am gresit, din comentarii. Dar imi doream foarte mult de acopar mai in detaliu acest topic pentru ca, mai mult decat orice altceva, bateriile din gloria the sprinter au starnit reactia clasica: Sunt scumpe domne. Deci, per total, pot sa spun cu certitudine ca nu, nu sunt deloc scumpe prin comparatie cu niste baterii pe gel. Si inca nu am intrat in detalii despre cum se incarca si se descarca, acolo e alta drama fantastica pe care vreau sa o discut intr-un episod viitor, notabil mai geeky decat asta. Dar bateriile astea sunt definitia expresiei „Sunt prea sarac sa-mi cumpar lucruri ieftine”

Acum ca am vorbit despre cum dimensionezi un sistem si ce baterii pui, in urmatorul blog o sa povestim despre panourile solare si controllerele care … ma rog … le controleaza. Si acolo avem de despicat firul in patru si e un aspect la fel de important ca cel al bateriilor. Sper ca v-a placut textul si sper sa ne citim cat mai curand!

Articolul Despre bateriile din Camper apare prima dată în CamperVan Fest Romania.

If you want to stay offgrid, somehow you have to have power from somewhere that you can consume. Whether you want a light to read by, an outlet for your laptop or to charge your phone, that power has to come from somewhere. And in this article I want to see where the energy comes from, how it is stored and how it is consumed from different types of batteries. Let’s review them in the first phase and see what we really end up with:

We have the normal lead acid car batteries, then we have deep cycle gel, we put lithium-ion in the list although meh and lithium iron polymer or lifepo4. The lead-acid battery is designed for traction, i.e. to give you power to start the car. It is not designed for constant consumption and will deteriorate quickly. We also get rid of Lithium-ion because they are not really common and they are quite dangerous, sometimes having quite interesting and violent exothermic reactions. We’re sticking with deep cycle and lifepo4, which we’ll call lithium from now on for ease.

We will compare the batteries according to several criteria: purchase price, weight, lifetime, number of cycles and DoD or depth of discharge, total production. Sure, we can go into much more detail but we said let’s just focus on the most important stuff. I would make a mention here that we are talking about standard lithium batteries and not aftermarket balancing cell variants or DIY solutions. Sure, they can be done, but it’s a hassle and 3 out of 5 people I know who have had them done have problems with them. So, to keep the balance, we take 2 batteries from the same manufacturer and compare them.

We will choose a Victron AGM 100Ah and a Victron LiFePO4 100Ah also, that is 1280Wh or 1,28kWh. Of course, the first thing we notice is the very, very different acquisition cost. On Darcom Energy’s website, the AGM version is 1800 RON and the lithium version 7100 RON and from there things separate quickly. The next easily intuited difference has to do with weight, and I find that to be an extremely important aspect of a camper. In the case of the 100Ah variant, the lithium is less than half the weight of the AGM. As capacities increase, the difference becomes 1 in 3 or even 1 in 4, as deep cycle batteries are usually quite heavy. We will come back to the question of weight in relation to Depth of Discharge, because it is a very important issue. So we’ve established so far that lithium is lighter and more expensive. We call these elementary empirical observations.

Moving on, we come to life as number of cycles, which is influenced by this Depth of Discharge. A deep cycle battery has an optimum DoD of 50%. This means that out of 100Ah in our standard battery, we can use 50Ah before it starts to degrade quite seriously. In the data sheet on Victron’s website, they inform us that at 50% discharge we have 600 battery cycles. Good. So in the life of this battery, we can use 600 times each 50Ah. To keep a balance, we still stay at 50% DoD and look at the lithium data sheet. For the same specifications, in the 2022 version of the batteries, with a similar DoD, the same battery supports 5000 charge cycles, so 8.3 times more cycles. But this is not the most relevant feature of these batteries, or lithium in general, but the fact that they support a DoD of 80%, where they have 2500 cycles. So unlike a deep cycle where you can draw 50Ah from a 100Ah battery, here you can draw 80Ah from a battery of the same capacity. The normal lifespan of a gel battery is 5-7 years, whereas the lifespan of a lithium battery is 15-20 years, so add that to the list of notable differences.

And here we come back to weight, because we originally calculated the weight at purchase, which defines how much you pay FAN Courier to get your battery home. But now, with the new data, we calculate according to available energy. If we can get 80Ah out of the lithium battery and it weighs 15 kg, to get the same energy out of the gel we need a 160Ah battery weighing 47 kg. And lo and behold, I added a black ball to the gel, or white to the lithium, or whatever you want to call it.

With all this information, we go back to costs and there are two important aspects: the price per kWh at purchase and the price per kWh over the lifetime of the battery. Clearly, gel wins hands down at 1400 RON per kWh while lithium jumps to 5500 RON per kWh. Let’s go back a bit to the number of cycles and DoD to calculate the lifetime price per kWh. We take strict DoD 50%, and for gel we will have 50Ah i.e. 0,6kWh x 600 cycles so 360kWh over the lifetime. For lithium we have 50Ah, so the same 0.6kWh x 5000 cycles so 3000kWh over the lifetime of our battery. We divide by the purchase price and the result is that gel costs 5 lei per kWh and lithium 2.36 lei per kWh, so less than half.

To recap: cost of acquisition, 1-0 to gel. weight 1-1, recover lithium, DoD 2-1 for lithium. 3-1 life cycles for lithium. Price per kWh purchase, point for gel, so 3-2. Finally, price per kWh per operating period, 4-2 for lithium. And then there was the difference in lifespan from … let’s say 7 years on gel, as I’m feeling generous, and 15-20 years on lithium. So 5-2 and the match is over. I agree that this option has a higher purchase price, but together we have shown that you actually come out better on every relevant score. For a long time I’ve been trying to get these calculations down on paper. I’m sure I misspoke here and there, I said watts instead of watts hour or whatever. I’m sure we’ll find out together where we went wrong from the comments. But I really wanted to cover this topic in more detail because, more than anything else, the batteries in the gloria the sprinter sparked the classic reaction: They’re expensive, ladies. So, overall, I can say with certainty that no, they are not at all expensive compared to some gel batteries. And I haven’t gotten into the details of how it loads and unloads yet, there’s another fantastic drama I want to discuss in a future episode, notably geekier than this one. But these batteries are the definition of „I’m too poor to buy cheap stuff.”

Now that we’ve talked about how you size a system and what batteries you put in, in the next blog we’ll talk about solar panels and the controllers that … well … control them. And there we have to split the difference and it is as important as the batteries. I hope you enjoyed the text and I hope to read you soon!

Articolul About Camper batteries apare prima dată în CamperVan Fest Romania.

Din punctul meu de vedere, tot ce inseamna offgrid se bazeaza pe energie solara. Sigur, exista si cazuri in care offgrid se face cu generator, dar nu prea fac subiectul disutiei noastre. Dar, daca ne bazam pe energie solara, trebuie sa o captam cumva si sa o bagam in baterii. Azi vreau sa vorbim strict despre panouri iar in episodul viitor sa abordam tema controller-ului solar, pentru ca si acolo este o aventura. Nu o sa vorbim insa despre brand-uri. Exista atat de multe variante de la Victron, LG, Canadian Solar, Nitecore, Poweracu, Solaewatt si tot apar si apa. In principiu diferenta dintre cele ieftine si scumpe o sa fie durata de viata si randamentul real. Dar, pentru sisteme asa mici ca un camper, parerea mea e ca sunt irelevante diferentele. Pentru o ferma cu mii de panouri, nu sunt dar in studiul nostru de caz, impactul generat de diferenta de calitate cred ca este minimal. 

Panourile sunt de multe feluri, flexibile, semiflexibile, rigide, monocristaline, policristaline, amorfe sau powerfilm si tot asa. Si, pe cat de multe feluri sunt, pe-atat de multe puteri pot avea. Si evident, vine intrebarea: care-i bun pentru mine? Iar ca sa raspundem la asta trebuie sa vedem ce vrei sa faci cu el, ce spatiu ai sa il pui si ce trebuie sa alimenteze. 

Prima diferenta importanta intre panouri este constructia: Rigid, flexibil, semiflexibil. Cele rigide sunt varianta cu rama metalica, ce se prind cu bride sau suruburi pe camper, roofrack-ul van-ului sau portbagaj. Cele semiflexibile se prind cu un dublu adeziv deja existent sau care se poate aplica, direct pe caroserie sau pe elementele unde incape. Iar cele flexibile sunt cumva destinate overlanding-ului. Sunt mici, se impaturesc, pot avea puteri foarte rezonabile si se scot cand campezi. Personal, pe Gloria, noi avem un panou de 300w rigid prins cu 6 bride serioase pe roofrack, ca sa nu plece nicaieri. In principiu, varianta asta e super ok pentru mai toate nevoile noastre. Variantele semiflexibile sunt poate cele mai slabe in lista deoarece au durata de viata cea mai mica si se incing cel mai mult. Pe scurt, daca nu vorbim de un semiflexibil amorf se calitate foarte buna, nici nu mi-as bate capul sa ma gandesc sa montez asa ceva pe vreun camper sau masina de overland. Vom reveni si vom detalia un pic mai incolo toate motivele pentru aceasta observatie. Ultimele sunt panourile flexibile care au castigat foarte mult teren in ultima vreme, atat prin faptul ca se pot strange foarte usor, dar si pentru ca au un randament foarte bun si pot fi repozitionate in functie de soare, spre deosebire de variantele anterioare care, in principiu, cam stau locului.

Mai departe avem monocristalin, policristalin, amorf sau powerfilm. Pe scurt, pe termen lung, varianta monocristalina este cea mai scumpa per w dar cu dimensiunea cea mai mica pentru putere echivalenta. In general sunt rigide si, la fel ca si varianta poli, nu apreciaza in mod special temperaturi foarte ridicate (peste 25-30 de grade). Diferenta principala dintre mono si poli are de-a face cu forma cristalelor. In cazul lui mono, dupa cum spune si numele, vei avea un singur cristal, pe cand in cazul unui panou poli, panoul va arata oarecum ca un geam spart. Aceste inconsistente in forma cristalelor fac electronii sa ramana pe alocuri blocati intre cristale si duce la o eficienta ceva mai scazuta. Dovada este faptul ca un panou policristalin va fi cu aproximativ 25% mai mare decat unul monocristalin de aceeasi putere. Cel mai mare dezavantaj al acestor tipuri de panouri este scaderea randamentului la caldura. Un panou are nevoie de lumina, nu de caldura pentru a functiona, iar temperaturile de 40-50 de grade la care ajung vara panourile le scade eficienta cu pana la 20%. Si aici revin la ideea de rigid montat versus semiflexibil lipit. Faptul ca cel rigid are loc sub el pentru ventilatie si pentru a se raci ii asigura atat un randament superior cat si o durata de viata notabil mai mare. Panourile amorfe sunt, cel putin azi, cele mai eficiente din punct de vedere al randamentului in toate situatiile de iluminare dar si din punct de vedere al temperaturilor de lucru, avand complet alt principiu de functionare decat cele traditionale. Dar, aceasta eficienta vine cu niste minusuri, cum ar fi un pret si o dimensiune mult mai mare pentru aceeasi putere. Traditional, deci, panourile monocristaline rigide sau flexibile sunt cea mai buna varianta daca luam in considerare pret de achizitie, randament si durata de viata.

Hai ca am intrat prea adanc in probleme tehnice. Sa ne relaxam acum cu niste matematica, normal

Evident, pornim de la intrebarea clasica: „De cat trebuie sa fie panoul meu pentru rulota?”. Pai, daca e sa o luam cat mai simplu si usor, raspunsul meu o sa fie intotdeauna: pune cel mai mare panou care incape. N-am auzit pe nimeni sa spuna „Uite-am pus doua panouri dar trebuia doar unul”. Mai degraba am auzit „N-a bagat panoul suficient, pe cale de consecinta nu e curent, deci e berea calda”. Dar, lasand sfaturile mele nesolicitate la o parte, hai sa vedem cum calculam real un consum. Pai, hai sa pornim ca in primul clip, de la cat consumam zilnic. Avem …. cat zisesem acolo, parca 1280Wh parca. Ne uitam la numarul de ore de stralucire a soarelui pe zi, pentru fiecare luna in care iesim, cu aproximatie si taiem cam la jumate. Deci, daca as merge in Iunie cand am sa zicem 6 ore de soare, avem 1280 impartit la jumatate din orele de soare, adica la 3. Rezulta un panou de 426w care ar putea sa umple la loc tot ce consum eu intr-o zi de stat offgrid. Exista multiple variante de calcul, unde nu se reduce la 50% ci la 70% sau 75% dar mie-mi place sa fiu conservator si sa gandesc un sistem care sa ma ajute mai mult decat estimez ca am nevoie. Si putem vedea treburile astea. Daca intram pe bluetooth si ne conectam la controllerul Smart Solar sau pe VRM, putem vedea un istoric foarte detaliat si putem calcula exact ce productie avem. In cazul meu, un panou de 300W imi produce undeva intre 1 si 1,5Kwh intr-o zi insorita. Desigur, am avut zile cand nu a produs nici 300w si, de fapt, de alea trebuie sa avem grija. Ca pe soare se descurca toata lumea. Deci, cred ca am elucidat si acest mister.

Voiam sa discut si despre chestiile conexe cum ar fi cabluri, presetupe, conectori si sigurante dar, ca sa nu ne lungim prea tare, hai sa lasam aceste detalii pentru episodul despre controllerele solare. Important azi era sa vorbim doar despre panouri. Daca ar fi sa simplificam si sa alegem ceva concret dupa toata discutia, recomandarea mea ar fi un panou monocristalin rigid pentru rulote, autorulote sau van-uri si, pentru ca in general spatiul e un subiect sensibil la overlanding fara indoiala un flexibil monocristalin, cum ar fi Dokio de 220w care mi se pare o varianta excelenta spentru masinile de overlanding. Sper ca v-a placut articolul si … in urmatorul, citim despre controllerul solar care ne ajuta.

Articolul Alegerea panoului solar pentru autorulotă apare prima dată în CamperVan Fest Romania.

In my view, everything offgrid is based on solar energy. Sure, there are cases where offgrid is done with generator, but they are not really the subject of our discussion. But if we rely on solar energy, we have to capture it somehow and put it into batteries. Today I want to talk strictly about panels and in the next episode we’ll tackle the topic of the solar controller, because even there it’s an adventure. But we won’t talk about brands. There are so many variants from Victron, LG, Canadian Solar, Nitecore, Poweracu, Solaewatt and they still appear and water. Basically the difference between cheap and expensive ones will be the lifespan and the actual yield. But for systems as small as a camper, my opinion is that the differences are irrelevant. For a farm with thousands of panels, there are not but in our case study, the impact generated by the difference in quality I think is minimal.

Panels are of many kinds, flexible, semi-flexible, rigid, monocrystalline, polycrystalline, amorphous or powerfilm and so on. And as many kinds as they are, so many powers they can have. And obviously, the question comes: which one is good for me? And to answer that we need to see what you want to do with it, what space you want to put it in and what it needs to power.

The first important difference between panels is the construction: rigid, flexible, semi-flexible. The rigid ones are the metal-framed version, which attach with flanges or screws to the camper, van roofrack or boot. The semi-flexible ones are attached with an existing or applicable double adhesive, directly on the bodywork or on the elements where they fit. And the flexible ones are somewhat intended for overlanding. They’re small, they stink, they can have very reasonable powers and they come off when you camp. Personally, on the Gloria, we have a 300w rigid panel clamped with 6 serious flanges on the roofrack, so it doesn’t go anywhere. Basically, this variant is super ok for most of our needs. Semi-flexible variants are perhaps the weakest on the list as they have the shortest life and heat up the most. In short, if we’re not talking about a very good quality amorphous semi-flexible, I wouldn’t even bother thinking about fitting one of these on any camper or overland car. We will come back and detail a little later all the reasons for this observation. The latter are the flexible panels that have gained a lot of ground lately, both because they are very easy to tighten, but also because they have a very good yield and can be repositioned according to the sun, unlike the previous variants that, in principle, are pretty much stationary.

Further we have monocrystalline, polycrystalline, amorphous or powerfilm. In short, in the long run, the monocrystalline variant is the most expensive per w but the smallest size for equivalent power. In general they are rigid and, like the poly variety, they do not particularly appreciate very high temperatures (above 25-30 degrees). The main difference between mono and poly has to do with the shape of the crystals. In the case of mono, as the name says, you will have a single crystal, while in the case of a poly panel, the panel will look somewhat like a broken window. These inconsistencies in the shape of the crystals cause the electrons to get trapped between the crystals and lead to a somewhat lower efficiency. The proof is that a polycrystalline panel will be about 25% larger than a monocrystalline panel of the same power. The biggest disadvantage of these types of panels is the decrease in heat output. A panel needs light, not heat, to work, and the 40-50 degree temperatures that panels reach in summer reduce their efficiency by up to 20%. And here I come back to the idea of rigid mounted versus semi-flexible bonded. The fact that the rigid one has room underneath for ventilation and cooling ensures both superior performance and a noticeably longer life. Amorphous panels are, at least today, the most efficient in terms of efficiency in all lighting situations but also in terms of working temperatures, having a completely different operating principle than traditional ones. But, this efficiency comes with some minuses, such as a much higher price and size for the same power. Traditionally, therefore, rigid or flexible monocrystalline panels are the best option when considering purchase price, yield and lifetime.

Let’s not get too deep into technical issues. Let’s relax now with some math, naturally.

Obviously, we start from the classic question: „How big should my caravan panel be?”. Well, if we’re going to keep it as simple and easy as possible, my answer will always be: put up the biggest billboard that fits. I’ve never heard anyone say „Look we put up two panels but we only needed one”. Rather I heard „He didn’t put the panel in enough, as a consequence there’s no power, so it’s warm beer”. But leaving my unsolicited advice aside, let’s see how we actually calculate a consumption. Well, let’s start like in the first clip, from how much we consume daily. We have …. as I said there, about 1280Wh I think. We look at the number of hours of sunshine per day for each month we go out, roughly, and cut it by about half. So, if I were to go in June when I have say 6 hours of sunshine, we have 1280 divided by half the hours of sunshine, i.e. by 3. The result is a 426w panel that could replenish everything I consume in an offgrid day. There are multiple options where it doesn’t come down to 50% but 70% or 75% but I like to be conservative and think of a system that will help me more than I estimate I need. And we can see these things. If we go on bluetooth and connect to the Smart Solar controller or VRM, we can see a very detailed history and calculate exactly what production we have. In my case, a 300W panel produces somewhere between 1 and 1.5Kwh on a sunny day. Of course, we’ve had days when it didn’t produce even 300w and, in fact, that’s what we have to take care of. Everyone can do it in the sun. So, I think I’ve solved that mystery too.

I was also going to talk about the related stuff like cables, presets, connectors and fuses but, to keep it short, let’s leave those details for the episode on solar controllers. The important thing today was just to talk about panels. If we were to simplify and choose something concrete after all the discussion, my recommendation would be a rigid monocrystalline panel for caravans, motorhomes or vans and, as space is generally a sensitive subject for overlanding, without doubt a flexible monocrystalline, such as the 220w Dokio which seems to me an excellent choice for overlanding cars. I hope you enjoyed the article and … in the next one, we read about the solar controller that helps us.

Articolul Choosing the solar panel for your car apare prima dată în CamperVan Fest Romania.

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Articolul Lorem ipsum dolor sit a met, consectetur apare prima dată în CamperVan Fest Romania.